UNDERWATER LIFE

AMERICAN EEL

Sallie Phillips and Bud Maaser, No 2 of 2002

Several years ago there was an elderly gentleman at Gilgo who kept eel pots in the lagoon. At the time I was intimidated by eels and avoided going near those traps. Recently, I've come across some interesting items about eels and decided to do some research about them.

As the order of Anguilliformes, there are many varieties of eels, worldwide. The East Coast North American eels (anguilla rostrata) are called common eels or American fresh-water eels. They can be found in a very extensive geographic range: from the southern tip of Greenland to the Atlantic coast of Venezuela; throughout the Caribbean and Gulf of Mexico; and inland up the Mississippi and down the Saint Lawrence Seaway and the Great Lakes. They also have the broadest diversity of habitats of any species in the world. The American eel is found in freshwater ponds, lakes and rivers, in brackish estuaries and in the open ocean.

American eels are notable for the long-time mystery about their spawning habits and mistaken ideas about their characteristics. For as long as people in America caught eels they did not know until 80 years ago where they spawned. Fishermen knew that adult eels went down the streams of the Atlantic drainage but then they disappeared. In the 1920's it was finally discovered that they mated and laid their eggs in the Sargasso Sea, between Bermuda and Puerto Rico. The Sargasso Sea is also the spawning grounds of the European Eel (anguilla anguilla). It provides the highest salinity in the Atlantic Ocean and it is warmer to greater depths. Both of these eels lay their eggs in deep water, up to a depth of 1500 feet.

This act of leaving fresh water to spawn in salt water is the opposite of Pacific salmon running upstream to spawn. Salmon are referred to as "anadromous" (meaning up channel), while European and American eels are "catadromous" (down channel). Actually, American eels are only partially catadromous since the male eels don't totally leave salt water. They stay in brackish water in the estuaries near the coast. It is the females that travel up stream, sometimes slithering across damp grass or digging through wet sand, to fresh-water rivers, lakes and ponds.

When the adult female American eel reaches about 5 feet in length and around 10 pounds, which may take from 5 to 20 years in her fresh-water habitat, she migrates down stream to the ocean. As she passes through the brackish territory of the adult male eels, which have only grown to approximately 2 feet, they both migrate to the weed (sargassum) filled Sargasso Sea. Just before the reproduction migration, the eels stop feeding and physical changes occur. Their mouths become smaller; their jaws weaker; their digestive system shrinks to make space for the developing sex organs; their eyes and pectoral fins grow larger; and their body pigments change. As they enter the open seawater their bodies turn silvery which makes them less visible to predators in the ocean. And, the larger eyes improve their deep water vision. The silver eel migration down stream, made on only stored energy, may take up to a year and after mating and egg laying the exhausted adults die. Each female may lay as many as 20 million free floating eggs which the males cover with milt.

The eel eggs, which were deposited in very deep water, hatch into pelagic larvae. Called leptocephali, they are from ? to 1? inches long, thin, transparent, and leaf-shaped as they emerge from the ocean depths. These larvae, so transparent that each vertebra is visible, drift on the ocean surface with the currents feeding on plankton. Drifting with the Gulf Stream, it takes from six months to a year to reach the North American Coast. Along the way, after they reach about 2? inches, they metamorphose into round bodies more like their parents. At this stage, they are called glass eels. They accumulate in "glass walls" at the mouths of rivers, along the coast, in great hoards, feeding on fish, crabs and other invertebrates. Still transparent and about the thickness of a pencil, the glass eels start to darken and turn opaque as they get accustomed to the lower salinity. As they acquire pigment they are called elvers. Male elvers remain in the estuaries and the females continue to migrate upstream, sometimes over tremendous obstacles. As the elvers continue to grow, they develop a light underside and darker upper side. Now called yellow eels, they are yellowish to greenish brown on the top and grayish white under. The eels will remain in the yellow phase for many years and further grow until they become sexually mature, which is when they show black and bronze dorsally with white ventrally.

An American eel, even though it resembles a snake more than a fish, is a true fish. Its pectoral fins are bluntly rounded and it has no pelvic fins but it has a single continuous dorsal, caudal and anal fin along its long and slender body. It's the ribbon-like fin, without spines, running from almost head to tail, that provides most of the thrust for the eel. As it swims, the water is alternately pushed from one side and then the other, but always backward, too. The eel can reverse the direction of the wave it creates so that it flows from tail to head, thereby allowing it to swim backward. And, because of its snake-like movements, it is able to get through very shallow marshy areas and even dew covered grassy fields. This elongated serpent-like fish has dense capillary systems close to its thick scaleless mucus-covered skin that can absorb oxygen directly from air or water but resist water loss from its body. The American eel has a small conical head with a broad mouth housing many sharp teeth.

American eels are nocturnal carnivores mostly feeding on insects, worms, fish, small crustaceans, and other invertebrates. Many people consider eels scavengers and claim that they feed on dead fish and animal matter as well as refuse. However, more recently, observers say that American eels seek out only living species.

Eels have been a source of food since Greek and Roman times. It was considered a symbol of wealth to have a pond filled with eels. Around 350 BC Aristotle studied eels and determined that they emerged from the mud without fertilization as earthworms. It was not until the 1700's that an Italian scientist found the eel's gonads and proved that eels were fish. Prior to discovery by an Italian zoologist at the end of the 19th century, it was believed that the leptocephalus, eel larva, was its own species. And, it was only in 1922 when the spawning grounds of European and American eels were finally discovered to be the Sargasso Sea. It is interesting to note that the European eels and American eels, that both start out in the Sargasso and don't have living parents to show them the way, never make the mistake of going in the wrong direction when they migrate to their adult homes. An American eel has never been documented in Europe. Even though there are many similarities in their appearance and behavior, there is a genetic difference between the species; the American version has fewer vertebrae than the European species. Eels are valued as food in certain cuisines in America and even more highly prized in Asia and Europe. And as the demand for Japanese eels and European eels has far outstripped their stocks, American eels, usually elvers, are exported to Asia and Europe in enormous quantities. At the same time that the market demands have increased in the last two decades, the catch has been declining. Also, data suggests that due to harvesting pressure, the yellow eels are also declining.

Locally on Long Island, the Native American tribes speared eels for their sweet meat. They then stretched and dried the skins which they used for various things such as belts and decorations on their clothing and headdresses. In the mid 1900's Long Island baymen trapped eels in pots and took them to the smokehouses along the south shore. These were not cash transactions since the smokehouses kept half of the eels in exchange for their labor. For many years a favorite winter pastime was spearing eels through holes chopped in the ice in the creeks and canals along the Long Island South Shore. Traditionally the eels were smoked or fried and consumed with a favorite beverage.

BARNACLES

Sallie Phillips, No 1 / 2002

In the winter in any coastal community, you can see boats, floats, rafts and various other structures, which were pulled out of the water for storage, crusted with barnacles.  Within a few weeks of landing these water vessels the smell is quite awful from these dead and dying animals.

Barnacles are crustaceans which make them relatives of lobsters, crabs and shrimp not mollusks, like clams and mussels, as believed until 1830.  From the subclass cirripedia, these sedentary crustaceans live exclusively in marine environments, sometimes in intertidal zones where they are periodically out of water.  In their larval stage they resemble tiny shrimp swimming with the current until they find a suitable location for their permanent residence. 

In anywhere from one hour to a few days a barnacle then attaches itself, head first, to a hard surface using a brownish glue which is one of the strongest adhesives in nature.  The youngster begins its transformation into adulthood as it builds its “house”.  The barnacle secretes chitin, the calcium substance which will become hard plates to surround and protect it.  Six of these plates form a hard cone around the animal while four plates become a door which will open and close with the tide.  The barnacle needs to conserve moisture when it is not submerged in the water so it is necessary to close itself into its shell.  When the tide comes in a muscle opens up the door plates so the barnacle can sift the water for food. 

As mentioned previously, the barnacle attaches itself head first, so it’s the legs that are in place to gather its food.  Six pairs of feathery legs, called cirri, have sensory hairs which sweep through the water collecting plankton for food.  All of these legs are jointed and have gills for the absorption of oxygen.

As the barnacle eats, it grows and its home becomes crowded.  Other crustaceans, like crabs, shed their shells when they get too small.  So does the barnacle, but it doesn’t leave its plated home as it somehow enlarges its cone-like abode.  Some people believe that it creates a new, larger exterior surface while it secretes a substance to dissolve the inner, confining layer.

Most barnacles are hermaphrodites, meaning that they each have both male and female sex organs.  However, they can’t fertilize themselves and they rely on a neighbor.  They utilize a retractable sperm-containing organ which can reach outside its enclosure into another barnacle several inches away to accomplish fertilization.  This penis like organ is believed to be proportionally the largest in the animal kingdom.  The host barnacle broods its eggs until they hatch as minute one-eyed larvae, nauplius, and emerge from their parent’s shell.  They feed on plankton voraciously, growing into the cipris larva stage before settling onto a surface to create a new home as an adult.  A new generation begins the cycle all over again.

Barnacles’ main predators are sea stars and whelks which envelope the barnacle and force their valves open.  Mussels compete for growth space, often overtaking and smothering barnacles.  Algae can also smother a colony of barnacles. 

Barnacles range in color from white to pinkish brown to purple.  They are divided into two types; the acorn barnacles and the goose barnacles.  The acorn type, balanomorpha, attach directly to the dock, boat or rock.  They tend to grow in dense colonies with each individual measuring from less than an inch to 30 inches long.  Some may even live on turtles or whales.  The goose type, lepadomorpha, has a long stalk which attaches to the hard surface.

Sallie Phillips, No 4 / 2001

The bay scallop, Argopecten irradians, is a bivalve mollusk, meaning it has two shells.  It appears in a variety of colors and its shells each have about 17 to 20 ribs and a pair of nearly equal ears at the hinge.  Inside the shell is a single muscle that keeps the two shells tightly closed.  This abductor muscle claps the shells quickly and powerfully and the clapping action ejects water around the hinge propelling the scallop through the water, escaping predators like starfish and crabs.  It’s the abductor muscle, inside and near the edge, that is removed from the harvested bay scallop and used as food.

Scallops, unlike other bivalves, like clams, do not burrow into the sand/mud.  They lie on the bottom, mostly in shallow waters where eelgrass is found.  Around the scallop’s body is a layer of tissue that secretes the shell which is called the mantle.  At the edge of the scallop’s mantle is a line of blue eyes that can detect some movement and alert the animal to the presence of predators.  Bay scallops live less than two years and they mature and spawn at about one year. 

 In New York bay scallops are found mostly in the bays of eastern Long Island but they have also been harvested from the Great South Bay.  Since 1985 the bay scallop population has been devastated by brown tide blooms, particularly in the Peconic Bay.  Phytoplankton, the brownish organisms, which turn the water brown, prevent the scallops from feeding properly causing them to starve.  During these brown tide blooms the scallop’s reproduction ability is also depressed. 

Some towns in Long Island have started restocking programs which involve spawning bay scallops in trays and racks then releasing the juveniles into cleaner water.

This year in New York the bay scallop harvesting season began on October 1 and continues until March 1, 2002.  Recreational and commercial harvesters generally use scuba equipment, scallop dredges, and scoop nets.  The NY State DEC Marine Resources office certifies the waters which are open for harvesting and sets the size and catch limits. 

I make a bay scallop chowder by: melting 1/4C. of margarine; sweating a chopped medium onion; adding 5 Tbs. flour; slowly stirring in <1Qt. of skim milk until desired thickness; adding a 15oz. can of potatoes, diced; adding 3/4C. frozen corn kernels; and adding salt and pepper to taste.  When the chowder is the consistency and taste I want, at the very end, I add 5oz. of bay scallops and only continue cooking until the scallops are white and opaque.  I serve this as a hearty dinner for two.

BLUEFISH

Royal Reynolds, No 2 / 1993

Bluefish are the most popular marine recreational fish on the east coast.  They are formidable predators that grow up to 4 feet long and weigh as much as 30 pounds.  The record bluefish caught in New York State was caught in 1979 in the Long Island Sound and tipped the scale at 241lbs 8ozs.

The blue-backed, silvery sided carnivores wander erratically moving in large schools following the movements of their favorite prey.  They swiftly track down and attack other schooling smaller fish such as mackerel, herring, menhaden, and sometimes smaller bluefish.  Frantic feeders they continue the slaughter of smaller fish after they have fed to their fullest capacity.  Bathers have been nipped by bluefish on a feeding foray near shore.

Along the Atlantic coast bluefish migrate south to Florida in the winter and north again in the summer.  They keep to waters with temperatures above 40 degrees.

Called snappers, or sometimes tailors, young bluefish begin life in bays and estuaries where they grow large enough to catch after only 6 months.  As they feed on smaller prey like shrimp and anchovies in shallower water, snappers have long been a favorite of youthful anglers. 

In 1991 New York State established a 10 bluefish per person bag limit.  The law placed New York in compliance with the Bluefish Management Plan developed by the Mid-Atlantic Fisheries Management Council and the Atlantic States Marine Fisheries Commission.  Bluefish face millions of well-equipped anglers, as well as increasingly polluted and degraded habitats which could reduce their population.  By reducing and controlling the harvest of bluefish, adult as well as snappers, it increases the potential for fish to reproduce and it increases the number of pounds of bluefish available.  The bag limit is an investment in the future for commercial fishermen as well as sport anglers. 

Any sport fisherman who has reached the bag limit should consider the catch-and-release method as an alternative pastime.

COQUINAS

Sallie Phillips, No 3 / 2002

This summer there seems to be a bumper crop of coquinas at Gilgo Beach. I had a foreign visitor who was fascinated and collected handfuls of them to take home. It was then that I realized that most of my neighbors had never even noticed them.

Coquinas, donax variabilis, are tiny mollusks. These ?" to ?" pretty wedge-shaped clams come in a wide variety of striated pastel colors and white and are found on sandy ocean beaches in the surf zone where the water is warm. The miniature bi-valves appear on the beach surface to feed, as the wave breaks, and quickly bury themselves in the sand, as the wave recedes, and then resurface with the next wave.

Sometimes called wedge shells or butterfly shells, the two shells of these clams remain attached after the animal has opened fully when heated either in the sun or by a cook. With their beautiful colors, both inside and out, they really do resemble butterflies. Despite their small size, bunches of coquinas are boiled to make a chowder. In Coastal Florida, years ago, their shells were compacted together to make a cement-like building material.

FLOUNDER

Sallie Phillips, No 2 / 2000

As a kid in South Jersey I accompanied my dad on his fishing charters either trolling (for blues) or  bottom fishing (for flounders).  While my preference was blue fishing, I have always been fascinated by flounders and other flatfishes. 

The obvious feature of flounders, halibuts, and other flatfishes is their actual flatness.  They swim and rest on one side and both eyes are on the other side of their heads.  Young flounders start out normally oriented and at first they swim in an upright position, like other fishes.  But, early in life the eye that is on what is to become the lower side of the body migrates to the other side until it ends up towards the top of the upper side of the body.  This eye movement and change in swimming orientation, occurs before the young fish is an inch long.  Our local flounder, the summer flounder or fluke, has its eyes on its left side whereas the winter flounder, from farther north, has its eyes on its right side.  Other parts of the flounder’s anatomy are in the same position as other fish, including its mouth, which remains centered, unlike the sole.  Its fins are on opposite sides of its body.  Its gill covers are also on each side of its body, one opening upward the other downward.  Expelled water from the lower gill is usually pumped out through the upper gill.  A flounder can get away from predators by gulping water and ejecting it through its lower gill, which causes it to rise vertically from the bottom.

The flounder rests on the side opposite its eyes; for the summer flounder that means its right side is its bottom side.  The bottom side of the flounder is away from the light and remains pale and colorless.  Only the top sides of flatfishes become pigmented.  And, the flounder has the amazing ability to simulate the color and pattern of the ground upon which it lives.  It has been demonstrated that a flounder placed on a red background, will mimic the red color on its top side within a few days and seem to disappear.  This chameleonlike ability is its main defense against predators.  Because the color change takes a few days, the flounder in the meantime will disguise itself by digging into the bottom and covering itself with sand or gravel.

Unlike most fish, the flounder has the ability to survive in both salt and fresh water.  The brackish water in inlets and bays is a perfect habitat for flounder.  It often moves upstream to feed at high tides and then lies stationary on the bottom waiting out the ebb tide, to ride the next incoming tide further upstream.  A poor swimmer, the flounder relies on the rising and falling tides to help it swim.  It can swim, if it must, by undulating its body up and down.  Its frill-like dorsal and anal fins, which run the length of its body, provide some momentum. 

Although a flounder can live and feed in fresh or brackish water, it must return to the ocean to breed.  It produces eggs on the sea floor under 80 or more feet of salt water.  The eggs float to the surface and when they hatch (in less than 2 weeks) the infants feed on tiny floating organisms and gradually move to shallow water.  Flukes or summer flounder grow to about 15 to 20 inches long

Sallie Phillips, No 3 / 2001

Long Island’s history and traditions are closely linked to clams.  The original inhabitants made purple beads from the clam shells to use as personal decoration and exchange currency.  The scientific name for the hard clam or Northern quahog is Mercenaria mercenaria, which brings to mind its use as money.  The names littleneck, cherrystone and chowder are all the same hard clam distinguished by size for market purposes, going from the smallest size to the largest.

Hard Clams are bivalve mollusks that live in shallow intertidal and subtidal areas of an estuary with a soft sandy bottom.  They burrow into the bottom leaving their “necks” or siphons exposed, one to pump in the water which contains the nutrients and oxygen necessary for their survival and the other to discharge waste.  Clams use gills to strain the water for planktonic food and the availability of their food source is a major factor that controls their rate of growth.  Water temperature and salinity are also growth rate factors. 

All hard clams begin adult life as males and about half of them become females as they mature.  Reproduction requires both sexes and occurs between May and August, when the water temperature reaches about 60 degrees.  Male and female gametes are discharged into the water and fertilization occurs.  The resulting free-swimming larva rapidly goes through a few stages until it develops a differentiated shell and a foot.  At this stage it alternates between swimming and crawling.  Then it undergoes a metamorphosis and loses its swimming ability and becomes a bottom dweller.  As metamorphosis continues the young clam uses long filaments for attachment until it develops into a juvenile with siphons and the burrowing ability.

Larval development can take any time from one week to 24 days.  During this phase the early larval clams are at great risk of mortality.  The main factors that threaten the survival of hard clams through their larval and juvenile stages are predation, poor water quality, contaminants and a bay bottom unsuitable for burrowing.  To adult hard clams these factors become less of a threat and the primary source of the declining adult population is believed to be over harvesting.

Many physical factors make our Long Island South Shore Estuary a productive environment that has historically supported great numbers of hard clams.  The bay bottom, which is made up of sand, silt and beds of vegetation, is a

perfect substrate for clams.  There is a low volume of freshwater coming into the bays which have a shallow depth, significant tidal change and the interruption of only five inlets along the 75 miles of barrier beach fronting the estuary.

 The shallow depth of the Great South Bay is a good news/bad news factor.  The shallowness is a positive because it favors the resuspension of nutrients.  The tide and wind are available to move around and refresh the sandy bottom in the shallow water.  And, of course, most of the shallow water is in the photic zone.  A well mixed body of water supports phytoplankton productivity while making unusual algal blooms less frequent.  The bad news for clams in the shallow Great South Bay is the ease of harvesting.  A very small investment can put someone in the shellfish harvesting business, as many a college student in the 70’s can attest.

 The overall decline in the clam population in the South Shore Estuary is not attributable to a single factor, although overharvesting in the late 70’s is considered significant.  Decline in water quality, changes in bay salinity, illegal harvesting, improper management, reduced reproductive success, and impaired feeding relating to the presence of brown tide have all been cited and are being analyzed and addressed.  Hopefully, in the future we will see the return of an abundance of hard clams in the Great South Bay.

HORSESHOE CRABS

Bud Maaser, No 1 / 1994

 Horseshoe crabs are truly living fossils; they were already ancient when the dinosaurs appeared on earth. 

Not true crabs, more closely related to spiders, scorpions, and ticks, horseshoe crabs are classed as arthropods.  Four species of horseshoe crabs survive today; three in southeast Asia and one along the Atlantic and Gulf of Mexico coasts.

Every spring horseshoe crabs head for the beaches by the thousands in an primitive spawning ritual.  The smaller male hangs onto the egg-laden female and as they reach the water's edge the female digs in to lay her eggs.  She deposits thousands of greenish-gray eggs in sticky clusters as tens of other sperm spreading males crowd around the mating pair.  By some mysterious instinct the horseshoe crab knows to spawn and bury her eggs at the full and new moons when the tide is especially high.  In this way she protects her offspring since the water will not reach their nest for two weeks.

The embryos can withstand broiling heat and heavy rains in their sand covered nests.  After succeeding spring tides have covered the nests and gently soaked into the sand, on a midsummer night when the moon is full the larvae break out.  By kicking and crawling the baby horseshoe crabs make their way to the surface and the ebbing waves carry them into the ocean.

By the time they are adults the dome-shaped, dull brown horseshoe crabs can grow to about three feet long including their slender pointed tails.  Poor swimmers, they walk on the ocean bottom, moving with the tides to and from the beaches.  Tracking has demonstrated that horseshoe crabs rarely travel more than four miles from their spawning places.

Not considered edible, horseshoe crabs were ground-up and used for fertilizer by tidewater farmers and today they are used as bait by commercial eelers in the Chesapeake Bay.

Horseshoe crabs, however, have found a great purpose in medical research.  In research on human eye function they are playing an important role.  The horseshoe crab actually has 9 eyes: 1 lateral eye on each side of its shell; 2 small ones in the center; and 5 light receptive organs beneath its shell.  With this equipment the crab forms an image of its world although the exact role of its visual system on its behavior remains unknown.

For more than 60 years the lateral eye of the horseshoe crab has been studied by recording electrical impulses from its optic nerve.  The simple arrangement of the crab's eye (compared to the human eye) makes it easier to record and analyze the signals the eye uses to send information to the brain.  This research has given scientists important knowledge about how the human eye perceives contrasts and shapes and has led to a clearer understanding of some eye diseases that cause tunnel vision and blindness.

In other medical research horseshoe crabs are collected in nets; their blood, which turns blue from a copper based molecule in their systems, is collected; and they are returned to the sea.  (See Maaser article)

In the water horseshoe crabs have few natural predators.  Loggerhead turtles sometimes rip through their legs and tear out their gills.  Sharks have been caught with horseshoe crab remains in their stomachs.  Undoubtedly, MAN is the crabs' worst enemy by destroying their habitat and polluting their waters.

HORSESHOE CRABS GIVE IMMUNITY

Bud Maaser, No 1 / 1994

Horseshoe crabs have become blue blood donors for humans.  The crab is immune to endotoxins, ubiquitous germs which are harmless to humans unless they enter the blood stream.  In the blood, endotoxins cause septic shock, a well-known danger in hospitals and battlefields, which has no antidote.  Endotoxins account for over 50 percent of hospital acquired infections and a fifth of all hospital deaths.

In the 1960's, researchers discovered that horseshoe crabs could fight off endotoxins because an extract from the crab's blood, Limulus Amebecyte Lysate (LAL), clots in the presence of the germs.  LAL is used by pharmaceutical companies to test medical equipment and drugs for the presence of endotoxins and the tests have "extraordinary accuracy".  LAL is also being used to diagnose spinal meningitis and to test for impurities in computer chips;.  Researchers report that the blue blood crabs may soon be able to produce an antidote for septic shock. Not bad for a horseshoe crab, one of the oldest inhabitants of the sea!

MORE ABOUT HORSESHOE CRABS

Sallie Phillips, No 1 / 1998

In our Winter 1994 Issue Bud Maaser wrote an article about the scientific studies being conducted to unlock some of the mysteries of the Horseshoe Crab, particularly its unique blood characteristics and its compound eyes.  Fascinated by Horseshoe Crabs, I thought I’d pass on more interesting facts about these ancient animals.

A Horseshoe Crab is not a crustacean at all.  It’s the sole surviving member of a class of sea animals (Merostomata) that originated 600 million years ago and are all extinct except Limulus, the Horseshoe Crab.  It is a distant relative of spiders and scorpions.  The Limulus was on hand for the arrival of snails, clams, fish, amphibians, insects, dinosaurs, birds and mammals.  It was so well adapted that it survived and needed no evolutionary improvements.

The Horseshoe Crab is protected by two pieces of armor on top.   The wide horseshoe shaped shield covers the head-thorax area and the triangular shield behind covers the abdomen.  These two sections are hinged together making the armor flexible.  When burrowing, the animal shoves its front shield ahead and bends its back shield downwards thereby giving itself forward thrust.  The plow-like edges of the front shield cut into the sand also while it is stationary, helping to keep it upright.  When it is does get upset it jabs its pointed tail into the sand and flips itself upright again.  The long pointed spine-tail is itself unique.  It is attached by a ball and socket type joint which can rotate 360 degrees around.

Because the Horseshoe Crab’s hard armor is not expandable.  The animal, as it grows, needs a new covering several times until it gets to its full size of two feet long.  When it molts it squeezes its body out through a gap at its front edge.  Then it secretes a new shell made from sclero-protein (<75%), chitin (<25%) and organic material (1%).  At first the new shell is pliable and allows the Horseshoe Crab a growth spurt.  Until the shell hardens it is very vulnerable, so the animal spends most of its time buried below the low water line in the sand.

The walking and eating equipment of the Horseshoe are protected under the dome of the front shield.  Its little mouth is in the middle and a pair of short limbs with pincers are on either side of it.  Four pairs of legs for walking are around the mouth.  The legs are jointed in the same manner as human wrists and they have big claws at their ends.

Out for a meal, the Horseshoe roots out sand worms, soft shell clams and other mollusks.  After the prey is caught in the leg claws, it is passed down to the spiny leg bases, just outside the mouth, which act as jaws.  The catch is chewed before it is wadded into the mouth.  Then the meal goes down the gullet into a crop and into a gizzard lined with “teeth” which further grind it up before it is passed into the gut.  Indigestible pieces are burped up.

The Horseshoe doesn't have to dig at random to find its favored soft-shell clams.  Chemoreceptors which are connected to the leg-based jaws signal the location of the prey for the Horseshoe.  It can find clams from as far as three feet away with uncanny accuracy, according to recent experiments.

Horseshoes stay near the shoreline mainly in depths of 35 to 40 feet.  During the winter they dig into the bottom in deeper waters and retire.  In the spring, with warming waters and longer days, they revive their activity.  At the time of the highest tides and the fullest moon thousands of adult Horseshoes head for the beaches to participate in a huge communal egg-laying party between the high and low tide lines.

The males get to shore first and the females must pass through a crowd of zealous fathers.  The competition is great because there are many more males than females.  A successful male will hang onto his partner’s back with a special hook.  The female will continue beachward dragging him along.  Other males may join the pair until she is dragging a procession, each male “hooked” onto the tail of his predecessor.  At the proper location in the shoal water the female gouges a shallow hole and deposits several hundred eggs.  The male(s) sheds sperm over the eggs and fertilization takes place in the nest.  When the egg laying job is done the Horseshoes swim off to feed in deeper water. 

Of the many thousands of eggs laid, many are never fertilized; many are swept out of the nest by the tide and gobbled up by fish; and many become delicacies for shorebirds.  Nevertheless, enough eggs do make it.  The hard egg coat ruptures a few days after being laid.  It is replaced by a clear membrane and the embryo continues to develop.  Some are ready to hatch when the next high tide comes in to toss them about.  The sand grains break the membranes and the Horseshoe young go down the beach with the tide into the ocean so to continue the presence of these living fossils in our world. 

JELLYFISH

Sallie Phillips, No 4 / 1998

This past June I was stunned to observe huge numbers of “baby” jellyfish around Cedar Marina.  I had never seen such a great concentration in one place.  Later in the summer I was not surprised to note an increased abundance of jellyfish along the beach at Gilgo.  I decided to do a little research on these annoying but fascinating creatures.

Jellyfish make up two classes of coelenterate invertebrates.  The term jellyfish usually refers to the free-swimming, gelatinous organism called the medusa.  The medusa is the form that the animal takes during its sexual stage.  The other stage in which reproduction is asexual is the bottom-dwelling polyp stage. 

The jellyfish (medusa) has two main developmental layers, the endoderm and ectoderm.  It has no head, a nervous system without a brain and it has a gut but no anus. The body is symmetric, either radially or about an axis.  Medusae are bell shaped and swim slowly by contracting their muscles around their perimeter.  Generally, however, they are transported by the water currents.  Their transparency is due to the fact that medusae bodies consist of less than 1 percent organic matter, the rest being water.

Jellyfish have a one year life cycle.  In the summer the medusae produce eggs and sperm that unite to form larvae which will spend the winter attached to anything substantial at the bottom of the estuaries, bays and near-shore ocean areas.  By the following April the next generation of polyps have been formed.  The stalk-like polyps start to break up into segments as the water temperature warms.  Each segment becomes unstacked (as from a stack of poker chips) and begins to grow quickly as the medusa form with the bell shape and tentacles beneath. 

There are three types of jellyfish common to the Long Island waters.  The moon jellyfish is a colorless gelatinous disc which has four rings on its top and has over two hundred short tentacles under.  It doesn’t get larger than six inches in diameter.  The sea nettle has a smaller and whiter bell but it sports longer (up to 3 feet) tentacles.  The lion’s mane jellyfish is the largest of the varieties found around Long Island.  It is generally larger than a foot across its reddish-purple bell and its tentacles can stretch over 50 feet.

Jellyfish don’t stalk their prey, they bump into their meals as they float with the water currents.  Adult medusae use their tentacles to stun their prey, usually small fish, and push their meals under their bells into their mouths.  Young medusae use their tentacles to scoop zooplankton into their mouths.  The stingers which line the tentacles of jellyfish are called nematocysts.  As they touch the potential prey they shoot a tiny barb at a speed which is one of the fastest movements in the biological world.  Depending upon the variety of jellyfish the venom deployed by the nematocysts can range from mildly annoying to lethal. 

Jellyfish have only few natural predators - sea turtles and sunfish.  Except in certain Asian cuisines, jellyfish are generally not consumed by humans.  For 500 million years nothing has come along to disturb the existence of these creatures.

KILLIFISH

Sallie Phillips, No 2 / 1998

Killifish (also called Killies) is the common name for any of more than 100 species of fishes which inhabit fresh, brackish and coastal marine waters from southeastern Canada to South America.  Usually less than 12 inches in length, they are commonly used as bait.  The word “killifish” comes from an old Dutch word meaning stream or creek. 

The Common Killifish is one of the most prevalent small fishes in shallow coastal waters.  It is usually found in schools in weedy, muddy places in marshes, bays and mouths of rivers.  This species prefers brackish water but it is also found in fresh and salt water.  A very hardy fish, it has the remarkable abilities to: survive marked changes in temperature and salinity;  live in highly polluted waters; and live out of water for a considerable length of time.  Spawning occurs from April to August in shallows thick with heavy vegetation.  The young grow rapidly and reach maturity by the following year.  During the winter this fish will bury itself in the mud.  It is a voracious feeder and eats almost any small plant or animal form.

Common females are larger than males and have brown-green above and are lighter on the lower sides and belly.  Breeding males are more silvery on their lower sides, with yellow on the belly, anal fins, ventral fins and edges of the dorsal and caudal fins.  Their sides have 15 narrow, silvery vertical bars and numerous blue white and yellowish spots.  A black spot on the rear part of the dorsal fin appears in both sexes.  Young of both sexes have a varying number of dark bars on their sides. 

Of the three races of Common recognized, the northern race ranges from Labrador to Virginia and grows to about 5 inches in length.  The Common Killifish is an important source of food for other fishes and extensive bait fisheries for it have been developed on Long Island for use in the sport fisheries for fluke and snappers

The Striped Killifish is found from Massachusetts to Florida and is longer than the Common.  The adult male has an olive back with yellow sides, belly and fins (pectoral, pelvic and anal).  15 to 20 black vertical bars appear on the sides and a black spot on the last rays of the dorsal fin.  The adult female is olive on the back and silvery under usually with 2 or 3 black longitudinal stripes on the sides.  The young of both sexes have 7-12 vertical black bars.

Other smaller (less than 3 inches) Killifish found around Long Island’s salt meadows in brackish water include Lucy’s Killifish and Broad Killifish and Rain-water Killifish.

A Killlifish relative, the Top Minnow or Gambusia is particularly valued in our area.  Usually olive above, gray on the sides and pale on its belly, it has dusky markings on its scales which form irregular dark dots.  The female reaches 2 1/2 inches and the male is smaller.  Top Minnows are so named because of their habit of feeding at the water’s surface as they are equipped with upturned mouths adapted for that purpose.  They consume large quantities of mosquito larvae on the surface of brackish water, making them very important in the reduction of the biting mosquito population.

MORE ON KILLIES

Sallie Phillips, No 2 / 1998

Last summer, George Sweetman, who has operated a bait business for many years, reported to me that he believed that the Suffolk County Vector Control application of pesticides on the wetlands were killing off the Killies and had also made him sick.  He, his father before him, and now his son have amassed decades of experience with bait fish along the barrier beaches and the Great South Bay.  Now, he maintains that he has witnessed a decline in the Killie population.

In an effort to find out more about the status of Killies in and around the Great South Bay and bordering tidal wetlands, I contacted the Town D.E.C. and was recommended to Mark Malchoff at New York Sea Grant.  What follows are notes from my conversation with Mr. Malchoff:

1. There is no hard data on bait fish populations. Any reported "shortages are usually not permanent".  Any decline is slight and the "year in year out the wild stock is holding up".

2. 10 bait dealers were surveyed on Long Island from Brooklyn to Patchogue and the average harvest was 1260 quarts per year per dealer.  It is estimated that there are 300 bait and tackle shops on Long Island.  Because the size of bait fish varies, the count per quart is from 20-150.

3. Mr. Malchoff doesn’t think that the Vector Control’s efforts are directly harming the Killies however, by eliminating mosquitoes, Killies lose a food source. 

4. Possible causes of Killie loss would be habitat degradation and over fishing.  (see 2.)

5. Mosquito ditches could cause a habitat degradation for Killies.  The spartina marshes, the preferred habitat for Killies, are flushing easier because of the ditches and predator fishes have access to the marshes and the Killies.  However, the ditches have been in place for 4 decades so, by now, a decline should be evident unless it is so gradual as to be unnoticeable.

6. 3 local species include fundulus (Common Killies), fundulus magalis (Striped Killies) and heteroclitus (Mummochogs)

7. Peterson’s guide says there are 10 species in Atlantic.  Luciae (Lucy’s) is listed from Massachusetts to North Carolina.  In addition to the Killifish above the Sheepshead Minnow is also in the spartina marshes in our area.

* see Vector Control Response under Mosquitoes

MERMAID’S PURSE

Sallie Phillips, No 1 / 2000

 One of the items on the scavenger hunt list which we use for the Educational Program is “a black egg case with points at each end”.  Typically the fifth graders have no trouble finding them on all over Cedar Beach.  Known by many names most people call them “mermaids’ purses”.

The black leathery egg case, about 3 inches long including the points, holds and protects a developing skate.  A shark relative, the skate is in the family of rays.  It’s body is flat and it has broad wing-like pectoral fins which meet in front of its head. 

Skates are harmless creatures that spend the day partially buried in sand on the ocean floor and come to action at night to hunt for shellfish, which they crush with their powerful flat teeth.  They propel themselves along the sea bottom by gracefully undulating their large fins.  There are over 200 species of skates worldwide.

The female skate, of most species, produces egg capsules in pairs, with a single embryo developing inside each one.  After several months the young skate breaks open a weak seam between two of the horn-like points at the end of its capsule and swims free.  The case, the mermaid’s purse, is hollow and light and eventually washes ashore.

The mermaid’s purse, looking rather bizarre, is really a wonderful piece of engineering on which the skate’s survival depends.  A mother skate creates a capsule inside its body by producing collagen-like fibers from a row of glands inside of her reproductive tract.  In the case of the hedgehog skate, these fibers are arranged in 35 different layers, held together by a gluey substance.  The layers are oriented in different directions like plywood and create a tough resilient material to protect the developing skate from predators. 

All fish embryos need a steady supply of oxygen to grow.  The typical fish egg is covered by a gelatinous covering and the necessary oxygen diffuses easily to get to the embryo. 

The skate’s tough fiber capsule is a different situation.  This egg case is actually a little water pump.  Water, and its valuable oxygen, is pumped into the capsule through slits in the outer edge of the points.  In the dynamic flow of the ocean, water around the four corners of the capsule moves a different speeds and different pressures.  Water enters at high pressure through one slit and, moving toward a part of the capsule surrounded by water at a lower pressure, is sucked back out.  This internal current fills the capsule with a new supply of oxygen-rich water about every 30 minutes.

Some sharks also lay an egg case, but without the horn-like points.  Slits along the side of their rectangular capsules also flush the water in and out.  The skate egg case’s points are more than decorative, however.  The skate embryo supplements the passive pump action of the capsule by its own effort.  The embryo has a string of muscle at the end of its tail which disappears after it hatches.  The embryo snakes this disposable tail section into one of the points and starts beating it furiously.  As the tail throbs, it causes waves that travel down the length of the point, carrying the water in the capsule out through the slit in that point.  As the water is pushed out one slit water is drawn into the pod through the other slits to replace it.  By the action of the skate embryo’s tail one hundred times more oxygen rich water is drawn through the capsule than the slits can provide with their passive pumping.  As the embryo develops it wiggles around inside its pod and slips its tail in and out of different points, beating it constantly.

As previously mentioned, shark embryo pods don’t have points and the pods’ slits provide adequate water pumping/refreshing for their development.  The reason that the shark embryos don’t need the additional tail action is that the shark mothers place their egg capsules off the ocean floor, attached to seaweed, coral, etc., where there is a steady flow of water.  Skate mothers can lay their eggs anywhere because their offspring can survive in slow-moving water by making their own flow.  Those four horn-like points on the mermaid’s purse are more that just decorative, they’re crucial.

MULLET

Sallie Phillips, No 2 / 2004

A mullet, Mugil cephalus, is often the "catch of the day" for an osprey. The common striped mullet is found throughout the world, and, in the Atlantic waters, from Cape Cod to Brazil. Mullets seldom grow over one foot long in the north but can be found up to 30 inches long in southern waters. They range in weight from 3 pounds to 12 pounds. The striped mullet is olive green or bluish-grey above with silver shading and 6 or 7 distinct horizontal black bars on each of its sides. It has a white underside. Its dorsal fin has 4 weak spines and is separated from a second soft dorsal fin. The pectoral fins are high on the shoulders and the pelvic fins are abdominal. The striped mullet has a forked tail fin. It has a blunt nose and a flat head between the eyes. A membrane covers part of each eye from the side. The mullet's mouth is small and there is a fleshy knob at the tip of the lower jaw.

Schooling fish, mullets swim over mud and in lagoons as they feed on small algae and detritus that is found in the mud. They are known to travel several hundred miles up rivers, but spawning always takes place in the ocean.

Mullets are known for their jumping ability; they can sometimes clear the water by several feet. Mullets are not generally considered rod and reel game fish. They are usually brought in by nets, although their jumping abilities often facilitate escaping. A mullet is very fatty fish; it is said that it is the only fish rich enough to be fried in its own fat.

MUSSELS

Sallie Phillips, No 2 / 1999

Some months ago I promised a STBF member to do an article on mussels, “Maybe include a recipe for mussels”.  In my search for material I found many more negative articles about mussels than informational passages.  Several species of mussels are, in fact, very destructive to the environment, structures and shipping.  Zebra mussels, for instance have disrupted the food chain in the Great Lakes and blocked the intake pipes in water treatment plants. 

Like clams and oysters, mussels are bivalves.  All bivalves are aquatic.  Bivalves are mollusks in which the mantle cavity has been greatly enlarged in size, and whose gills, in addition to their respiratory function, act as a food sorting organ.  The edges of the mantle are partly fused to a pair of siphons that pump and circulate water through the mantle cavity.  And then currents caused by cilia pass this large quantity of water over the gill filaments.  Food particles are sorted, passed to the food grooves and continue into the stomach.  Nonfood particles are passed to the mantle edge and thrusted outside.  The shell and mantle are large enough to cover the foot and mantle cavity. 

The mussel shell consists of two halves or valves which are of equal size and shape and are connected by a flexible ligament whose resilience keeps them slightly open at the bottom.  The valves of the shell can be shut by contraction of the muscles.  The springlike ligament tends to hold the shell open, while the muscles enable this bivalve to shut tight.  The mollusk’s foot acts as either a digging organ or a secretor of the attaching fibers, byssal threads.

The common mussel, or Mytilus edulis, has a violet-blue, elongated triangular shell and is from 1 to 3 inches in length.  The outer covering, or periostracumis blue-black and shiny.  There are a number of tiny teeth at the very tip in the interior of both shells.

This mussel attaches itself by means of thread-like anchors to almost any object which is left above water by the retreating tide.  Called the byssus, this attaching matter is very strong.  And sometimes, immense numbers of common mussels, all stuck together, can be seen covering rocks, bridge supports and other submerged structures.  A search along the beach after a storm sometimes reveals masses of mussels attached by the tenacious byssys to beached pieces of broken docks or other flotsam. 

Common Mussels are widely distributed throughout all northern seas and they are highly regarded in many cuisines.

HAROLD’S MUSSELS

3 lb. cleaned, smooth mussels

1/2 cup olive oil

1 onion, sliced fine

3 or 4 cloves garlic, chopped

chopped parsley to taste

1 tsp. oregano

3 bay leaves

2 cups canned tomatoes with juice

1/2 tsp. dry mustard

1 cup black olives

1 cup stuffed green olives

fresh ground pepper, to taste

In a large pot heat oil, sauté onions and garlic until soft.  Add parsley, oregano, bay leaves, tomatoes, dry mustard, olives and pepper.  Bring to boil; add mussels and simmer until shells open.  Discard unopened shells.  Serve in soup bowls with Italian bread. (Serves: 4-6)

This recipe by Dr. Harold Schade from Gilgo Beach was published in the Oak Beach Gulls cookbook, Galley of the Gulls - Volume II New Horizons

ANNE’S CLEANING METHOD

·         Place mussels in a mesh bag and close very tightly.

·         Place mesh bag into a canvas bag and close tightly.

·         Place the canvas bag and contents into a washing machine with a two or more beach towels.

·         Set the washer on a cold water gentle wash for 2 to 4       minutes; use no soap.

Anne Grossman from West Gilgo Beach gives us this method to clean mussels and keep from scrubbing our knuckles raw.  She promises that, “They will come out ‘crystal clear’”.