TROPICAL WAVES
Seiners, divers, and saltwater aquarists reported early arrivals of tropical fishes along the Jersey Coast in 1988 and 1989. Most tropical fishes found this far north have hitched a one-way ride as larvae drifting in the warm Gulf Stream water that continually skirts the eastern seaboard. These fish are observed each spring immediately after the inshore waters are warm enough to permit their survival, which may coincide with the passing of a warm-water gyre or ring that has swung off from the Stream and moved towards our coast. Such conditions in '88 and '89 are probably what rewarded fishwatchers and collectors with almost a month of extra time in the spring to find these seasonal visitors to our shores.

Apparently those fishes that don't end up in aquaria are destined to die when the water temperatures take a nose dive in October and fall below 60º F. This usually occurs around the middle of the month after a tropical storm or cold front passes and strong offshore winds from the west blow the warm water out to sea, causing temperatures to plunge over a 24 hour period.

Some notable finds included a trumpetfish (Fistularia tabacaria), the only species in our area with a combination "normal" and whip-like tail. The naturalist Henry Collins said of the trumpetfish, "To our eyes, one of nature's outstanding oddities. Perhaps that is how man looks to the trumpetfish." The Bigeye (Pseudopriacanthus altus), which is noted for its bright red color and large golden eyes, was also found.

Both were stranded on the ocean beach or in ocean tidepools after a November storm at Sandy Hook. They have been reported north of here and in cooler waters in the summer, but none survived the stress of the rapidly changing water temperature and are new additions to the list of fishes recorded on the beach here.

Unprecedented numbers of burrfish (Chilomycterus schoepfi), invaded our waters in the summer of 1990. One of the porcupine fishes, the stout little burrfish grows to the size and shape of a big lemon by the end of the summer. Although it has been reported as far north as Maine in August, it is a decidedly warm water creature and fish north of the Carolinas apparently die off in the fall.

Specimens were especially common in our nets in Sandy Hook Bay, and hardly a day passed from August through October, that we didn't catch them. Some were brought to me by puzzled, local fishermen, and I found unusual numbers of dead specimens on the beach after the waters cooled down in October.

Burrfish are not especially rare in New Jersey but their striking appearance and their ability to swell up like puffers when they are threatened attract considerable interest with people who have never seen one before. They also add a tropical flavor to our waters in the summer. This was their year to thrive and conditions we don't fully understand will probably favor another species this year.

(For images of Sandy Hook fishes, click here.)
(To identify a fish you caught, click here)

HAZARDOUS HYDROIDS (Also read about helpful Hydroids)
Each year discarded plastics, fishing lines, and netting take a tremendous toll on some of the more noticeable marine animals. The specter of dolphins, seals, birds, and turtles drowned or suffocated is dramatic and troubling even to those who are not particularly interested in these endearing animals. But there is also a great loss of life among the lesser creatures of the sea that often goes unnoticed.

Last fall I happened upon yet another hazard to marinelife while I was surf casting for bluefish. My lure snagged a large bundle of rope, which is unfortunately, not an unusual occurrence in our coastal waters (even for good fishermen). It turned out to be the catch of the day. When I picked through the 10 pound mass in search of my lure and any other fishing equipment that is routinely found tangled up in such flotsam and jetsam, I realized it was swarming with marinelife. This surprised me because the material did not look as though it had been in the water very long. Fouling organisms quickly colonize litter that sinks or does not wash ashore because many attached creatures are not very selective about which firm substrate they settle on.

Scuds and skeleton shrimp are commonly found on all sorts of firm substrates like rocks, pilings, and even trash if they have a decent coating of fouling organisms like barnacles, mussels, and algae. Although such a community was lacking, there still was a good number of these common crustaceans on the frayed, half-inch thick nylon rope mass. Both creatures are abundant in our waters and a close look at any subtidal surface usually reveals them.

What caught my eye though were dozens of hermit crabs that seemed to be clinging to the frayed portions of the rope. They were long-clawed hermit crabs, the smaller and more common of two local species. On closer examination I discovered that they were hopelessly trapped, not by the frayed threads, but by colonies of a hitch-hiking hydroid that covered their shells. The hydroids, known as "snail fur," were entwined with the threads.

Snail fur (Hydractinia echinata) is one of the plant-like Hydrozoans, a class of the Coelenterates, the phylum which also houses the more familiar jellyfishes and corals. Living snails that plow through the sand or empty shells that tumble with the waves and currents are not suitable homes for snail fur because of the abrasive action of the sand. But once the shell is commandeered by a hermit crab, most of its surface, except where the shell is dragged along behind the new homeowner and scrapes the sand, is kept out of the sediments and is available for colonization by the fur.

With a hand lens I saw three different types of polyps, feeding, reproductive, and defensive, that formed the sticky mat that got the hermit crabs into trouble. The crabs' shells were fixed so securely to the line there was no chance for escape, and it was only with some effort that I could pull them free from it. (Surely this is how George de Maestral was inspired to develop velcro while pulling burrs from the fur of his dog!)

The crabs' only chance for survival, and a slim one at that, would have been to bail out of their shells and happen upon an empty shell before they were preyed upon. If not, they were destined to tumble in the surf with the ropey mass, collecting more of their cousins, until they starved to death or were tossed on to the beach to dry out and die. Unless, of course, they were lucky enough to be caught by the right, unlucky fishermen.

(For more images of Sandy Hook hydroids, click here.)

A SUSPICIOUS SHINER
This past summer we caught an adult shiner (Menidia menidia) with a deformed spine. It had a pronounced downward bend to the cervical vertebrae. This type of deformity was reported previously in this bulletin and other publications. What was unique about the specimen is the fact that we were able to keep it alive in an aquarium for a time and observe its swimming behavior. The motion was remarkably similar to fishing lures that are articulated in the middle and presumably attract a predator's attention because they move like an injured fish.

In theory it makes sense to try to imitate such actions in designing a lure, but questions arise. If this particular fish's swimming was so conspicuously different from a normal shiner and yet it managed to survive to adulthood, does its swimming style (and the lure's design and action in the water) actually make it any more attractive to predators? Is swimming style (and lure design) really that crucial or was this just an incredibly lucky fish? I am probably not the person to study such a problem since my results when fishing are remarkably consistent, and humbling, regardless of the lures I use.

(To identify a fish you caught, click here)

Something to think about:

• What affects the physiology of tropical fish in cold water?
• What is the advantage of living as a colonial animal?
• What survival or defensive features can you find in these fishes?
• List products you use that could injure animals if they are disposed of improperly.