Mantis Shrimp, Squilla empusa

Well, beach walking has caused me to start researching again. Seems that I must be fond of finding weird crustaceans. Besides the barnacle, I ran across a Mantis Shrimp. It’s not a shrimp at all, but is in the crustacean class: Malacostraca. It has it’s own Superorder, Hoplocarida and a single order: Stomatopoda and Family: Squillidae. The one I found has a latin name of Squilla empusa. Spotted at dusk on Ocean Isle Beach, NC, it was just wiggling near it’s burrow. The Mantis Shrimp got it’s name from the fact that it looks like a cross between a preying mantis and a shrimp, but is neither.

When I started reading about it I found a large contingent of aficionados on the internet. It seems there are a lot of people who keep them in salt water tanks while others find them to be pests that have sneaked into their tanks in live coral. There are two different types, ones that spear their prey and ones that club their prey. The one seen here spears its prey. The ones that club their prey have been known to even break a fish tank.

There are 8 pairs of appendages. The first two are hairy and thin and used for cleaning. The second two are very large and shaped like scythes and are used to stab their prey (or your finger if you try to pick it up). The third through the fifth set are small legs that end in a flat oval shape called chelone. The chelone is used to bring food into the mouth. The last three pairs are long and thin and are used as walking legs. The sharp scythe-like appendage has 6 spines found at the last joint (Hickman 1973). Their strike is one of the fastest movements known in the animal kingdom, taking less then 8 milliseconds to strike, which is about 50 times faster than the blink of an eye (Squatriglia 2001; San Juan 1998, DBW 1998). These claws are strong enough to dig through sand, rocks and even lacerate a hand, which is why they are also known as "thumb splitters", "finger poppers", "killer shrimp" and "thumb busters" (San Juan 1998, DBW 1998, CIMS 2000).They live in sand burrows with many openings and can be found in off shore water up to 150 meters. The Squilla.empusa is a nocturnal carnivore that feeds mainly on soft bodied animals like fish, shrimps, krill, marine worms, snails and other mantis shrimp (CIMS 2000). http://animaldiversity.ummz.umich.edu/site/accounts/information/Squilla_empusa.html

Barnacles - Striped barnacle and Ivory Barnacle

I was walking near the pier on Ocean Isle Beach, NC and noticed all the barnacles on the pier pilings.
Surprise, surprise, these are crustaceans! The crustaceans you are used to seeing, lobsters, shrimp, and crabs are in the subclass Malacostraca, but barnacles are in the subclass Cirripedia. They have fewer appendages and segments and their organs are rearranged. In fact, the barnacles that are attached to surfaces are thought to be attached by their heads!
Most barnacles are hermaphroditic and they cross fertilize their eggs. They drift though the water and find a suitable place to attach. As they mature, their mantle secretes an external shell. They have plates that interlock by overlapping and in the center they have two sets of plates that act as a door. When in the water, the barnacle opens and closes it’s doors and it extends it’s cirri (feathery legs) and catches any plankton or detritus in the water. They are filter feeders. After they mature,they put out a chemical which attracts other barnacles. That’s why you will find them in clusters. Most live attached to firm surfaces like pilings (where these pictures were taken), rocks, oysters , boat bottoms or even turtles, whales and crabs .Early naturalists misclassified barnacles as mollusks
because of the outer shell-like structure.

This is a Striped Barnacle Balanus crenatus.
It’s interesting because in the North, it is white with grey stripes and south of Cape Hatteras, it’s white with purple stripes.


It is very similar to the Ivory Barnacle Balanus eburneus which is smooth and white. Seen below.


Someone sent me a video on bio-luminescence and camouflage in sea creatures and I thought it was very interesting.
Click on the link below to watch.
http://www.ted.com/index.php/talks/view/id/206

Sea Squirt, Tunicate (Sea Pork) and Parchment Tubeworm

November 30, 2007

It was a wonderful day on the beach. Still in the low 70s, the low tide revealed a lot, but, no great shells. In their place were a lot of tunicates and parchment tube worms.
The Tunicates have a common name of Sea Pork. Some types are called sea squirts because they will squirt water when picked up and squeezed. The picture of the brown sack like animal is a Sea squirt (I squeezed this one as I took the picture so you could see the water coming out of it).
“Sea squirts are immobile marine invertebrates which extract food (plankton and organic material) from seawater pumped through a brachial sac in their body cavity. They are called sea squirts because they squirt' seawater. The scientific name for this class of animals is Ascidiacea, so scientists often refer to them as 'ascidians'. They are part of a wider grouping (sub-phylum) of marine invertebrates called 'tunicates'. This sea squirt has been tentatively identified as a Styela plicata.
This invasive sea squirt is known by the name Pleated Sea Squirt. Its scientific name is Styela plicata (Lesueur, 1823).It is also known as the rough tunicate.

The pleated tunicate, Styela plicata is a solitary benthic (an aggregate of organisms that live in the bio-geographic region that includes the bottom of a lake, sea, or ocean and the littoral and supralittoral zones of the shore)(that’s got to be a super word to mean so much while saying it so succinctly !) tunicate believed non-native to the east coast and the western Atlantic, but occurring there in some abundance. The oval, upright body is covered with a tough and leathery cellulose-containing tunic, with numerous rounded warts and pleated grooves and a pair of short siphons.
Individuals range in color from light tannish white to gray. Thin red or purple stripes on the insides of the four-lobed siphons are evident as cross-shaped markings at the tips of the closed siphons. Individuals can be found singly or in groups (Carlton and Ruckelshaus 1997, Kaplan 1999, NIMPIS 2002, USGS, ISSG)

Styela plicata is a hermaphrodite, with individuals starting out as functional males and then becoming functional females later in life. Sequential hermaphroditism insures fertilization through outcrossing. Sperm and eggs are shed to the water column via excurrent siphons and fertilization is external. (Yamaguchi 1975, NIMPIS 2002).

Styela plicata is a sessile (permanently attached), benthic filter-feeder. The incurrent siphon takes water into a sieve-like pharyngeal basket that filters out food of the appropriate size class before water is pumped from the animal via the excurrent siphon. Styela plicata is among the most common introduced ascidian species worldwide. Despite considerable evidence supporting the contention that the organism is not native to U.S. waters, Styela plicata was originally described in 1823 from specimens collected from the hull-fouling community on a ship in Philadelphia PA. The organism was reported from U.S. coastal waters ranging from North Carolina to Texas in the 1880s, and had been reported from California by 1915. It is thought to be native to the Indo-Pacific region. (Carlton and Ruckelshaus 1997, Lambert and Lambert 1998, Lambert 2001).

Styela plicata is a widespread and common fouler of buoys, pilings, nets and other floating or submerged manmade structures. It is also a common fouler of aquaculture cages, bags, and nets. If fouling is severe costly cleaning of culture gear is required to avoid still costlier loss of stocks (Da Rocha and Kramer 2005).

http://www.sms.si.edu/irlspec/Styela_plicata.htm

Kingdom Animalia
Phylum Chordata
Subphylum Tunicata Lamarck, 1816 -- ascidies, sea squirts, tunicates,
Class Ascidiacea
Order Enterogona
Suborder Aplousobranchia Lahille, 1887
Family Polyclinidae Milne-Edwards, 1841
Genus Aplidium Savigny, 1816
Species Aplidium glabrum (Verrill, 1871)

Aplidium glabrum This is the name of the purple tunicate pictured to the right. It is a colonial (colony) species that has zooids in a clear tunic. I had sent a note with photos to Gretchen Lambert who helps publish the Ascidian News out of Seattle WA and she is the one who tentatively identified this animal for me. It seems that it is very difficult to definitively identify the tunicate without dissecting the zooids from the animal and viewing them under a microscope. I'm such a novice, that I have no idea what each zooid looks like. I will continue to research and try to find out. ( I guess my first item of business is to buy a microscope - one that I can take pictures with!)
It is interesting that when I was researching information about this tunicate that scientists have been trying to determine the cytotoxicity to certain types of cancer tumor cells. The research is very promising for the pharmaceutical industry.




"The Chaetopterus parchment tubeworm feeds by fanning water through its home tube with its wing-like legs (fan parapodia). A bag of slime is excreted from two feeding legs (aliform notopodia). Water flows into this bag and out through its side, trapping tiny algal and mud particles. At its bottom end, the bag is continuously rolled up into a ball by the food cup. Once the ball is big enough, the bag is rolled up entirely and the compact ball of mucus transported to the mouth over a conveyor belt of whipping hairs (ciliated dorsal groove). " Dr. Floor Anthoni www.seafriends.org.nz/indepth/invasion.htm

Atlantic Calico Scallop and Florida Fighting Conch

The Calico Scallop Argopecten gibbus (Linnaeus)
Is a bivalve ranging in size from 1-3 inches. It is almost circular in shape and has equally sized ears. The exterior of the right valve is white-yellowish and usually splotched or striped with colors of red or purple. The left valve is darker in color usually with red, orange or purple variegated with white or yellow- white. This scallop is commercially fished especially off both North Carolina and eastern Florida coasts. It is found only in the ocean and lives in 100 foot depths from Delaware to Brazil.
The live scallop has rows of eyes each having its own lens and retina, but it has no center of vision in its brain and probably can't form an image. It can however distinguish light and dark. It moves by opening and closing its shell. The dark variegated scallops are also calico but a chemical reaction occurred in these shells in which the calcium carbonate had been replaced with iron sulfide when the scallops were buried in the offshore muck and lacked oxygen.(Florida's Fabulous Seashells - Williams/Carmichael)

Florida Fighting Conch Strombus alatus (Gmelin)
is 2-4.5 inches and is a thick shell and is yellow-brown to reddish brown in color often with pale spots or stripes. It's axial ribs are crossed by spiral cords and gradually become larger and more separated and knobbed. It has a stromboid notch on its lower end of the canal. This notch is typical of all true conches - hence, they are in the family of Strombidae.
A herbivore, it feeds on red algae and is found offshore from North Carolina to Texas and Mexico. Like the Atlantic Calico Scallop above, it is also commercially fished chiefly for steaks, chowders and salads.

Common Paper Nauttilus, Cross-Barred Venus

The Common Paper Nautilus or Common Paper Argonaut is not really a shell in the true sense of the word. It is actually an egg case secreted by two arms of the female Argonauta argo (Linnaeus). Most shells will be secreted by the mantle of the mollusk, but not this one. I found this in the sargasso grass on Del Rey Beach, Florida on a recent trip there.
The animal is in the class Cephalopoda which is composed of the squid, octopus and nautilus. Most are predatory carnivores.
Only the female secretes the shell, the male Argonaut is much smaller and does not have a shell. They are usually found in tropic or temperate seas. The female can grow to the length of 2 feet and produce a shell as big as 14 inches long, these are nowhere near that size. They swim near the surface of the water and prey upon pteropod mollusks and small pelagic fish. Sailfish in turn, prey upon them.

Cross-Barred Venus, Chione cancellata (Linne) are one of the most plentiful shells on the island. They seem to come in a variety of colors depending on the sediment in their environment. They are heavy with strong, raised concentric ridges and rounded ribs that form a network of raised lines. Found in shallow waters, they are the main food source of the green and blue crab as well as moon snails. When you come across some with 'ready made holes for stringing', those have been likely drilled by the moon snail.

Seashore Creatures - Cannonball Jellyfish and Portuguese Man-of-War

Cannonball Jellyfish (Stomolophus Meleagris) Class Scyphozoa
I hadn't gotten around to putting these on the blog, but I definately enjoyed finding them. On the 8th of June, there were quite a few jelly fish and a few Portuguese man-of-war on the beach, along with a lot of sargassum weed.

The Cannonball Jellyfish is 5-7 inches high and 7-9 inches wide. It floats near shore and is found from the Chesapeake Bay to Texas, the Bahamas and the West Indies. The books don't have a caution about this animal.



The Portuguese Man-of-War (Physalia physalis) is another story.

It's class is Hydrozoa and It can be found up to 12 inches long and 6 inches high by 5 inches wide. It floats by being gas filled and is iridescent blue and pink with tentacles of different lengths, some being more than 60 feet long and containing stinging cells.

The books warn that it is highly toxic and "the tentacles contain one of the most powerful poisons known in marine animals and can inflict severe burns and blisters even when the animal is dead on the beach." (National Audubon Society Field Guide To Seashore Creatures)

I'm still just learning about everything on the beach, but, I sure knew enough to stay away from this!

Crenulated Pyram, Atlantic Oyster Drill, New England Basket Shell

Crenulated Pyram Pyramidella crenulata (Holmes) is a small (1/2 inch) shell with smooth, flat-sided whorls and deeply incised sutures. It's cream with tan blotches and lives in mud and in grass from the low-tide line to 50' sandy ocean bottoms. It can be found from North Carolina to Texas. It is a parasite that feeds on the soft tissues of other mollusks and marine animals.







The Atlantic Oyster Drill Urosalpinx cinerea (Say) Is a small shell measuring from 1/2 inch to 1 1/2 inch high. It's oval with an elevated spire and is grayish or yellow-white with a rough exterior with large axial ribs forming a pattern of raised wavy lines. It lives in sounds and inlets. Commonly found living in oyster reefs and on pilings. It's range is from Nova Scotia to Florida and is a carnivore that prefers barnacles and oysters. It drills a hole into the shell and feeds on the soft parts of the animal.
The New England basket shell, Nassarius trivittatus(Say) is sometimes called a threeline mudsnail, New England Dog Whelk or a New England Nassa is a small shell with a rough surface and strong axial ribbing with beaded whorls. It's between 1/2-7/8" high and is white to yellowish-gray. Southern specimens (as found in North Carolina) have 3 reddish-brown spiral bands on the body whorl. Located on sand and muddy sand and intertidally to water 300 feet deep, it's range is from Canada to Florida. It feeds on egg cases of the Northern Moon Shell and is a scavenger.