Life in the Shifting Dunes / A popular field guide to the natural history of Castle Neck, Ipswich, Massachusetts

Common Rockweed

(Fucus, several species)

Brown, flattened body

Central midrib

Stem has air bladders

The bladders are filled with air, and children like to squeeze them to hear their pop. These bladders cause the plant to float upright, thus keeping all its sides in contact with water.

Nodose Rockweed

(Ascophyllum nodosum)

Thin, round stem

No central midrib

When dried by the sun, this plant makes an interesting and lasting souvenir, for it turns a lustrous black.

Common Kelp

(Laminaria agardhii)

Broad, flat blade

Several feet in length

The kelps of the Pacific grow several hundred feet in length, making them the largest of the algae and among the very largest plants.

Fingered Kelp

(Laminaria digitata)

Many blades, extending like fingers on a hand

All kelps have a rootlike structure called a “holdfast” to serve as an anchor. Often tiny sea creatures dwell in among the holdfast. Why not take a look?

Perforated Kelp

(Agarum cribrosum)

Central midrib

Broad blade punctured with hundreds of holes

In Asia this kelp is farmed for food called agar. An extract of the plant, agar-agar, is used in the laboratory as a culture medium for bacteria and other disease-producing organisms.

Sea Lettuce

(Ulva species)

A sheet of green

This is a very simple seaweed that reproduces itself by fragmentation, each fragment growing into a new plant. Two common kinds are found at Crane’s Beach:

Ulva lactuca, which is the broad green “leaf”; Ulva lanceolata, which is in thinner, more ribbon-like strips.

Irish Moss

(Chondrus crispus)

Flattened, branching fronds

Purple in life, white when sun-bleached

Here is a very common tidal plant that has commercial value. It is called “Dulse” on the Boston markets, and a very delicious pudding is prepared from it (seamoss farine). Why not take some home and try it?

Polysiphonia

(Polysiphonia, several species)

Pink or red color

Branching, lace-like appearance

Sometimes called “Mermaid’s Hair,” these tiny plants are very common on the beach. There are many kinds of Polysiphonias, but a microscopic study is usually necessary to tell them apart.

Coralline Algae

(Coralline, several species)

White or pink limy covering

Appear jointed

These plants have the amazing ability of concentrating lime from the sea water and depositing it on their fronds, thus acquiring a stony, coral-like appearance.

ANIMALS OF THE SEA

Animals, in a kaleidoscope of unbelievable sizes, shapes, and colors, abound here at the margin of the sea. Specializations range from the single-celled body of the zooplankton to the multicellular body of the Seals and the occasional Porpoise.

Finger Sponge

(Chalina oculata)

Brown or tan color

In colonies of fingerlike projections

The most common sponge on Crane’s Beach is the Finger Sponge. Even a small piece may be identified by the holes on its surface, through which the animal filtered water. The strange appearance of this sponge has given it the repulsive name of “Dead Men’s Fingers.”

Crumb-of-Bread Sponge

(Halichondria panicea)

Pale green in life

Light tan or white when dried on beach

Crumbles easily

Only the most searching eye will discover this sponge, because it so closely resembles a dull uninteresting rock or pile of bread crumbs. When it has been freshly broken, it has a vile odor—a good clue to identification.

White Jellyfish

(Aurelia aurita)

Flattened body

Under 10″ in diameter

The tentacles dangling down from the underside of this jellyfish are covered with tiny stinging cells, which in this species do not penetrate human skin.

Pink or Red Jellyfish

(Cyanea capillata)

More than 10″ in diameter

Reddish center, yellowish sides

This jellyfish occasionally grows up to eight feet in diameter, with tentacles a hundred or more feet long. The stinging cells can painfully wound a swimmer, but you may examine a small jellyfish safely by placing your hand on the smooth dorsal surface and turning it over.

Sea Anemone

(Metridium dianthus)

Cylindrical, soft body

Tentacles at top give flower-like appearance

Generally very colorful

The “petals” of the Sea Anemone’s flower-like head are actually tentacles covered with stinging cells and used to stun its food. Generally found in the water at tide level, the Sea Anemone moves by walking on its single, base-like foot.

Clam Worm

(Nereis virens)

Jointed

One pair of paddle-like feet per segment

Two “tails”

Pinchers on the head (watch out!)

This is the best-known worm on the beach because of its desirability as fish bait. During the day it lives in its burrow in the sand, wandering forth at night and swimming about in the water, where it becomes easy prey for gulls and fishes. The skin is brilliantly iridescent in the sunlight.

Common Barnacle

(Balanus balanolides)

Common on rocks and shellfish

White, volcano-shaped shell

Two “barn doors” at top

This animal goes through life standing on its head and kicking food into its mouth with its feet! When it is submerged in sea water you can see its shell doors open and its feather-like feet sweep the water for microscopic food organisms. The limy shell first suggests a relationship with the clam, but body structure shows it to be a closer relative of the crab.

Shrimps

(Crago septemspinosus, the Sand Shrimp, and Palaemonetes vulgaris, the Prawn)

Hard, transparent shell

Long antennae

Paddle-like tail

These tiny tide-pool creatures look for all the world like the larger edible shrimp served in local restaurants. Actually, these miniature two-inch-long shrimps are edible also, and quite enjoyable if you have the time and patience to collect enough for a meal.

American Lobster

(Homarus americanus)

True Crabs

(Cancridae and Portunidae)

Football-shaped in cross section

Two large claws

Eyes mounted on stalks

The three very common True Crabs of Crane’s Beach may be found in one search of the tidal pools. They are:

Rock Crab (Cancer irroratus): A brick-red shell, somewhat granulated, with a black and yellowish undersurface.

Jonah Crab (Cancer borealis): Similar in color to the above, but its shell has a more sculptured surface.

Green Crab (Carcinides maenas): A greenish-colored shell. The last pair of legs end in sharp points, rather than being flattened like paddles.

Horseshoe Crab

(Limulus polyphemus)

Shell with horseshoe-shaped outline

Long, sharply pointed tail

Two immovable compound eyes

The Horseshoe is not a Crab at all, but is more closely related to the spiders, mites, and scorpions. In spite of its relations, the Horseshoe is a harmless creature whose only protection is its hard shell. Therefore it may be examined freely—a strange “living fossil” that has survived 400,000,000 years of evolution with very little change.

Oyster

(Ostrea virginica)

Mottled, unattractive shell

Gray splotches on inside surface

Even without pearls, our Oyster is worth many thousands of dollars a year to shellfish dealers because of its delicious flesh. Its tropical relatives are the pearl producers.

Mussels

(Mytilidae)

Blue-colored shells

Shells covered with black, horny skin

Living mussels are always found attached to rocks or pieces of wood by tiny threads of their own making. Two common mussels are:

Edible Mussel (Mytilus edulis): Smooth, velvety-blue shell identifies it. The animal within is edible and quite delicious. It is commonly utilized as food in Europe but less so here, where we have, and seem to prefer, the Oyster.

Ribbed Mussel (Modiolus demissus plicatulus): Similar to the above but with many distinct ribs radiating on the surface. The Ribbed Mussel is not considered edible. While not poisonous, it is most unpalatable.

Hardshell Clam

(Venus mercenaria)

Thick, round shell

Purple blotches on inside surface

Also called “Quahog,” “Little Neck,” “Round Clam,” or “Cherrystone,” the Hardshell Clam is another highly prized seafood.

Edible Clam

(Mya arenaria)

Fragile shell with egg-shaped outline

Wing extending out from inside top of left half of shell

These clams are found just a foot or so under the sand, and their empty shells are common on the beaches. This is the Softshell Clam, which we enjoy steamed, baked, or fried, as well as in New England’s famous clambakes and clam chowders.

Surf Clam

(Spisula solidissima)

Very large shell

Spoon-shaped trough at inside top of shell

This is the largest clam on the Atlantic seaboard, growing up to about seven inches in length. It is edible, and just one or two make a large chowder. The shell makes a fine ashtray and an unusual and useful souvenir.

Razor Clam

(Ensis directus)

Elongated brown shell

The Razor has a very large foot, with which it can often dig faster than the hand trying to discover it. Although delicious, the Razor Clam is seldom seen on the markets because it is so difficult to capture.

Snails

(Littorinidae, Thiasidae, and Naticidae)

Clams in a coiled shell

Several species are found at Crane’s Beach:

Periwinkles (Littorina): These have a wrinkled shell about the size of a thumbnail. Because they are able to withstand long periods without water, Periwinkles are often found high on a beach.

Rock Purple (Thais lapillus): Has a rough, white shell coming to a point at the top. This snail secretes a purplish dye that was used by the American Indians and the ancient Phoenicians to produce their “royal purple” dyes.

Moon Snail (Polinices heros): Large white shell with almost round shape. The Moon Snail lays its eggs in a sand “collar,” which is frequently discovered on the beach in its dry state.

Slipper Shell

(Crepidula fornicata)

Shell is boat-shaped

Tiny “seat” inside shell

This animal protects its bare underside by attaching itself to a handy rock with its suction-cup foot. Often there are enough of them to give the rock a warted appearance.

Starfishes

(Asterias vulgaris, and others)

Five-armed body

The Starfish seems to like Oysters as well as we do, and it opens them by sheer strength. Oystermen used to tear Starfish apart to destroy them, until they discovered that each arm has the ability to regenerate and become a whole starfish!

Sea Urchin

(Strongylocentrotus droehbachiensis)

Round body

Covered with spines

Here is a creature with a scientific name much too long for its size. Indeed, the name is said to be the longest in animal nomenclature. The Sea Urchin is a living fossil with four times as many extinct cousins as living ones.

Sand Dollar

(Echinarachnius parma)

Silver-dollar size and shape

Raised, star-shaped pattern on back

This is an animal of deeper water and so the bather seldom sees a live, heavily spined specimen. We find the dry, spineless shells on the beach. Wrap them carefully if you wish to take them home, because they are most fragile.

Pipefish

(Syngnathus fuscus)

Lead-pencil size and shape

Hard, bony plates cover body

One look at a Pipefish will convince you that it must be related to the Seahorse. It spawns late in the spring, the female laying her eggs in the pouch on the stomach of the male. The male carries these eggs kangaroo-fashion, until they hatch during the summer.

Silverside

(Menidia menidia)

Silver stripe running down a light side

These fish are also an important food item for the Gulls and Terns. Silversides run in schools of a hundred or more, which can be located by the flocks of birds gathered round overhead.

Skates

(Raja, several species)

Strange bat shape

Long ratlike tail

These are harmless fish resembling the dangerous Rays of the tropics, except for their habits. The egg cases of the Skate are rectangular, black, horny envelopes. They are commonly found on the beach, where they are called “mermaids’ purses.” If you find a fresh one and open it, you may discover a miniature Skate inside.

Killifish

(Fundulus heteroclitus)

Stout, olive-green fish

Rounded tail

The “Chub,” well known to fishermen, can live for a day covered only with a layer of damp seaweed. It does us a real service by feeding on the mosquito larvae in brackish water.

Sticklebacks

(Gasterosteus and Apeltes species)

Spines on the back

Very narrow base to tail

During the early summer months, the Stickleback builds a barrel-shaped nest, held together with gelatinous threads. After the eggs have been deposited, the male guards the nest with amazing vigor, considering his size.

Sand Lance

(Ammodytes americanus)

Knife-shaped body

Long dorsal fin (fin on back)

Protruding lower jaw

Thriving abundantly off the beach, the Sand Lance is an important item in the diet of shore birds.

FOR MORE INFORMED BEACHCOMBING

Thus begins our day of beachcombing. Every animal and plant of the sea has a tale to tell and some of the most exciting of all are found in this ribbon-like strip of water in the tidal wash.

For your further investigation, here is a list of reference books:

Charles M. Breder, Jr., Field Book of Marine Fishes of the Atlantic Coast. Rev. ed. New York: Putnam’s, 1948. $5.00

Ralph M. Buchsbaum, Animals without Backbones. Rev. ed. Chicago: University of Chicago Press, 1948. $8.00, text ed. $6.00

Rachel L. Carson, The Edge of the Sea. Boston: Houghton Mifflin, 1955. $3.95

Roy Waldo Miner, Field Book of Seashore Life. New York: Putnam’s, 1950. $7.00

Percy A. Morris, A Field Guide to the Shells of Our Atlantic and Gulf Coasts. Rev. ed. Boston: Houghton Mifflin, 1951. $3.95

Herbert S. Zim and Lester Ingle, Seashores: A Guide to Animals and Plants along the Beaches. New York: Golden Press, 1955. Cloth $2.50, paper $1.00

Ticks

(Ioxidae and Argasidae)

Body egg-shaped in outline

Very small head

Parasitic on human beings as well as animals

Ticks are quite common at the beach, but only the tourist who ventures into the woods will encounter them. From the tip of a blade of grass they hook on to a warm-blooded animal passing by. In removing a Tick some care is necessary so that the tiny head will not remain embedded in the victim. Ticks can usually be persuaded to let go if touched with a lighted cigarette or daubed with rubbing alcohol.

Harvestmen

(Phalangida)

Very small oval body

Extremely long, slender legs

Better known as “Daddy-long-legs,” these creatures resemble Spiders, but are not very closely related to them. They are perfectly harmless and cannot bite. Most of them feed on plant juices or dead insects.

True Spiders

(Araneida)

Body divided into two distinct parts

All have poison fangs

Many spiders are to be found on Crane’s Beach. Most are small, harmless, and difficult to identify. However, some of the general groups may be readily recognized:

Sheet-web Spiders (Linyphiidae): A small spider, usually less than a quarter of an inch long. Its sheetlike web identifies it.

Orb-weaving Spiders (Argiopidae): All of these spiders build their webs like a wheel with radiating spokes. The Orange-and-Black Garden Spider (Miranda aurantia), a large species infesting grassy places in the fall, is typical of the group.

Crab Spiders (Thomisidae): The Crab Spiders do not construct webs, but their crablike shape and the fact that they walk sidewise will identify them.

Wolf Spiders (Lycosidae): This spider hunts its prey instead of building a web and waiting for its meal to happen along. Wolf Spiders are often large and quite hairy. The holes you find in the sand dunes are nurseries constructed by the female Sand Dune Wolf Spider (Lycosa pikei).

Jumping Spiders (Attidae): “Jumpers” have a rather fat body that is heavily covered with hair. They too hunt their prey, often jumping several inches to capture it.

Sow Bugs

(Isopoda)

Flat, segmented body

Less than ten pairs of legs

The Sow Bug, commonly called the “Pill Bug,” is usually found hiding under a damp log. It is completely innocuous and will often roll into a ball when disturbed.

Centipedes

(Chilopoda)

Elongated, segmented body

Fifteen or more pairs of legs

One pair of legs per segment

The Centipede is usually found hidden in a moist place. It feeds on insects killed by a poison injected through its jaw. Although Centipedes occasionally bite a finger, their poison is so weak that the bite can be ignored.

Millipedes

(Diplopoda)

Hard, segmented, worm-shaped body

Two pair of legs per segment

Roll into a ball when disturbed

The Millipede is found in much the same habitat as the Centipede, under a board or rock or inside a rotten stump. It is harmless, and lives for the most part on decaying plants.

INSECTS: SIX-LEGGED ANIMALS

These insects have long, soft bodies and two long “tails.” The first stage in the Mayfly’s life is spent under water in one of the several swampy pools behind the main beach. Early in the spring it changes into the winged adult that is unable to eat. This adult lays its eggs and dies soon afterwards.

Dragonflies

(Aeshnidae, and others)

Two pairs of long, stiff wings

Two large compound eyes, which touch each other

Hold wings outspread when they alight

Dragonflies are often called “Devil’s Darning Needles,” but they are perfectly harmless. They frequent wet areas, where they feed on other insects—particularly mosquitoes!

Damselflies

(Lestidae and Coenagrionidae)

Two pairs of long wings

Large compound eyes do not touch

Wings folded over back when resting

Aside from their smaller, more delicate appearance, these insects look like the Dragonflies. They are found in the same places and have similar habits.

Short-horned Grasshoppers

(Acrididae)

Antennae shorter than body

Typical Grasshopper shape

Most Grasshoppers are strong fliers and are easily frightened into flight. The males may be heard singing during the day—a rasping noise produced by drawing the hind leg across the veins on the wing.

Crickets

(Gryllidae)

Antennae longer than body

Black or dark brown color

The commonest Cricket here is the Black Field Cricket (Acheta assimilis). The “singing” of the Cricket is produced by the male as he rubs his wings together. Of particular interest is the Snowy Tree Cricket (Oecanthus niveus), which chirps rhythmically. By counting the chirps in one minute and subtracting forty, then dividing this total by four and adding your new sum to fifty, you will have a rough estimate of the temperature in degrees Fahrenheit.

Praying Mantis

(Stagmomantis carolina)

Pale green color

Forefeet bent as though praying

Mantids were once rare in New England but in recent years seem to have been extending their range northward and are now quite common even in the grassy beach area. They are said to be the only insects that can look over their shoulders.

European Earwig

(Forficula auricularia)

Wings short, not half length of body

Two pincers on tail

The Earwig hides by day, coming out at night to feed on plant material. Since it does not bite with its pincers, it can be handled freely. Other species are occasionally found. The Seaside Earwig (Anisolabis maritima) is the largest New England earwig. It has more than twenty-four segments to its antennae, whereas the European has no more than fifteen.

Lygaeid Bugs

(Lygaeidae)

Four sections to antenna

Antennae end in club shape

Very few veins in forewing

The most common member of this group is the Red-and-Black Milkweed Bug (Oncopeltus fasciatus), which feeds exclusively on Milkweed. A small insect (Geocoris) also belongs to this group. It has a hammer-shaped head and may be found beneath dried seaweed.

Stink Bugs

(Pentatomidae)

Broad, shield-shaped insect

There are many kinds of Stink Bugs, so named because of the disagreeable odor they emit when crushed. Some are brightly colored and are commonly found on the fleshy dune plants.

Woolly Alder Aphid

(Prociphilus tessellatus)

White, woolly mass on Alder or Maple tree

The Woolly Aphid is found only on Alder and Maple trees and may be recognized by its downy appearance. Although it feeds on the tree, it is never common enough to do any damage. The wool is a secretion of wax protecting the insect.

Oyster-shell Scale

(Lepidosaphes ulmi)

Tiny oyster-shell-shaped body covering

Attached to bark of tree (particularly Poplar and Birch)

You must look very carefully to discover one of these insects. The young Scales have legs and move about during the month of June. Then they settle down, lose their legs, and secrete a wax shell over their bodies. These Scales are extremely common at the beach, but only the careful observer is likely to see them.

Common Lacewing

(Chrysopa, several species)

Delicate-green insect

Very large wings

Golden-colored eyes

In spite of its delicate shape, when caught the Lacewing emits an odor which has earned it the name “Stink Fly.” Its eggs are laid singly on long stalks because the young, called “aphid lions,” are cannibalistic.

Carrion Beetles

(Silphidae)

Body is soft but horny

Five segments in antennae

Usually found near dead animals

The Carrion Beetles lay their eggs on a dead animal, which they bury as a food reserve for their young. This habit has given them the common name of “Burying Beetles.”

Ground Beetles

(Carabidae)

Dark brown or black

Head narrower than mid-body

Usually have prominent jaws

The legs of the Ground Beetle are designed for quick movement. These beetles are mostly active by night. They are beneficial because they eat other insects.

Tiger Beetles

(Cicindelidae)

Bright green or blue, metallic

Head broader than neck

Run and fly quickly

The adult feeds savagely on other insects, killing them with powerful jaws—which can also nip your finger. The larvae are called “doodlebugs” and live in upright burrows in the sand, allowing their jaws to extend above ground to capture unsuspecting prey.

Click Beetles

(Elateridae)

When turned over, the insect snaps back upright

First body segment as broad as the last

Click Beetles are so named because of the resounding “click” they make when snapping up into the air after being overturned. The adults are strict vegetarians, so look for them on plants.

Scarab Beetles

(Scarabaeidae)

Large body, oval outline

Antennae terminate with fanlike segment

Body has “polished” finish

There are more than 1400 species in this group in the United States and more than 30,000 in the world. Two of the most common at the beach are:

May Beetle (Phyllophaga fusca): A large cylindrical brown body. Also called “June Bug,” in May and June it is frequently discovered at night flying to a light.

Japanese Beetle (Popillia japonica): The head and forebody are metallic green; the wings are copper color. Introduced from the Orient about fifty years ago, these beetles do great damage to many kinds of plants.

Snout Beetles or Weevils

(Curculionidae)

Small, roundish body

Dull, uninteresting color

Long tube (snout) on head

These are very common beetles on the dunes. Their long snout is used to drill into seeds and plant tissues. None of our species do great harm, but they have some unpleasant relatives—the Plum Curculio (Conotrachelus nenuphar) and the Cotton Boll Weevil (Anthonomus grandis).

Ladybug Beetles

(Coccinellidae)

Hemispherical shape

Brightly colored

Many kinds of “Ladybug” or “Ladybird” Beetles can be found at the beach. Some feed on plants and others on small insects. The insect-eating varieties are extremely valuable.

Fireflies

(Lampyridae)

A “tail light”

Elongated soft body

Head is not visible from above

The Firefly’s light is produced by the chemical reaction of a substance called luciferin. It is an almost perfect “cold” light, with practically no heat loss. The light is used to attract the opposite sex during mating. The larva of this beetle is the “glowworm.”

Swallowtails

(Papilionidae)

Large Butterflies

Tail-like extension on hind wings

The Tiger Swallowtail (Papilio ajax), with yellow and black wings, is the largest butterfly at the beach, and, indeed, the largest butterfly in America. In midsummer you may find one fluttering about flowering plants.

Cabbage and Sulphur Butterflies

(Pieridae)

Half-dollar size

White or orange wings

These butterflies are common wherever there is an open area such as the dunes. In other parts of the United States the caterpillars destroy great amounts of alfalfa and cabbage.

Milkweed Butterflies

(Danaidae)

Large size

Orange and black markings

The Monarch Butterfly (Danaus plexippus) is our most common species. Because of its bitter taste the birds won’t eat it.

Wood Nymphs

(Satyridae)

Butterflies with two large “eye spots” in brown wings

Large wing veins are swollen at base

Nymphs are found from sea level to the mountain peaks. Look for them in the Pitch Pine woods behind the beach.

Skippers

(Hesperiidae)

Very hairy Butterflies, even wings

Erratic, skipping flight

The Skippers look much like Moths. Their crazy, zigzag flight helps identify them.

Sphinx Moths

(Sphingidae)

Sphinx Moths frequently have a five-inch wingspread and

are called “Hawk” or “Hummingbird” Moths.

Saturnid Moths

(Saturniidae)

Very large, hairy moths

Large, feather-like antennae

Two species occur in our area:

Cecropia Moth (Samia cecropia): It is the largest moth in our area, having varying colors of brown and yellow.

Luna Moth (Tropaea luna): New England’s most beautiful moth, the Luna is pale green, with a brown leading edge on the forewing and a long tail-like extension from the hind wing.

Tiger Moths

(Arctiinae)

Yellowish-brown body

Three rows of black spots on body

The larvae of these moths are the well-known “Woolly Bear” caterpillars that are covered with a dense coat of rusty-red and black hairs. They are not beneficial. Two common examples are:

Salt-marsh Caterpillar (Estigmene acrea): This caterpillar is covered with rose-colored hair. It feeds on practically every type of leaf in the fall.

Webworm (Hyphantria cunea): It covers the ground for several feet with its silky web. In large numbers, Webworms can denude a tree in short order. Periodic outbreaks of these “Soldier Worms” are common at the beach.