r o m sound to sea 



Homegrown Critters 



Familiarity can breed indiffer- 

 ence. 



After all, the creatures of the 

 North Carolina coast are just garden- 

 variety fish, crabs and oysters. The 

 really interesting animals live in the 

 deep, dark reaches of the ocean. 

 Right? 



Wrong. More than likely, there 

 are a few things about our home- 

 grown beach creatures that you never 

 knew. Here's a sampling. 



• The male sea horse — not the 

 female — incubates the eggs of their 

 offspring in his brood pouch. The fe- 

 male passes her eggs to the male, who 

 fertilizes them in his pouch. Then, the 

 lining of the pouch thickens with folds 

 charged with blood vessels that carry 

 oxygen and food to the developing 

 embryos. In three weeks, the male ex- 

 pels the fully formed young by flexing 

 his body. 



• Before much was known 

 about starfish, irate watermen may 

 have unwittingly increased their popu- 

 lations. Starfish entangled in their nets 

 were cut up and thrown back to sea. 

 What the fishermen didn't know was 

 that starfish can grow new arms. And 

 in some species, one arm can regener- 

 ate an entire animal. 



• Bird feathers are made of kera- 

 tin, the same substance of human nails 

 and reptile scales. 



• The snowy and great egrets 

 were hunted to near-extinction in the 

 late 1 800s, when their feathers were in 

 great demand as decorations on 

 women's hats. The same trend nearly 

 decimated the least tern, which was 

 used whole to trim fashionable hats. 

 Laws were eventually passed to pro- 

 tect these birds. 



• Ospreys normally mate for 

 life, returning each year to the same 

 nest and adding branches. The nest 



grows over the years, sometimes 

 reaching 1,000 to 1,500 pounds. 



• The appendages of the horse- 

 shoe crab have unusual functions. It 

 uses its spiked tail as a lever if turned 

 on its back. Its legs provide locomo- 

 tion and grind food, much like teeth. 

 The food is then passed backward 

 through its legs into the mouth. As a 

 result, the horseshoe crab is unable to 

 eat except when walking. 



• Crustaceans are able to es- 

 cape a predator by breaking off one 

 or more legs at a specific joint spe- 

 cially adapted not to bleed. A crab, 

 for instance, can break off its own 

 leg to flee; or a predator can snap the 

 leg. A crab regrows the lost limb at 

 later molts. 



• The ghost crab is apparently 

 in the midst of an evolutionary 

 change from a past existence as a sea 

 animal to a future as a dry-land ani- 

 mal. Every day, it must return to the 

 ocean shallows from its home in the 

 upper beach zone to wet its gills. 



• Every autumn, the spiny lob- 

 ster exhibits an unusual migration 

 into deeper waters. In groups as large 



as 60, it walks along the ocean bottom 

 in single file, maintaining contact 

 with only antennae. It travels up to 30 

 miles over several days for reasons 

 unknown. 



• The loggerhead turtle is tem- 

 perature-sex-dependent (TSD), since 

 it has no X or Y chromosome to de- 

 termine sex. Instead, the sex ratio of a 

 loggerhead nest is determined by the 

 temperature of the sand at incubation. 

 Under laboratory conditions, as incu- 

 bation temperatures exceed 84.5 F, 

 more females are produced. As tem- 

 peratures cool, more male hatchlings 

 result. 



• The oyster changes sex repeat- 

 edly during its life. The grouper starts 

 life as a female and later becomes a 

 male. 



• Find a shell riddled with hun- 

 dreds of tiny holes? It was likely the 

 victim of a boring sponge or marine 

 worms. Orange-colored sponges at- 

 tach to a shell and secrete an acid sub- 

 stance that eats through the shell. Ma- 

 rine worms bore tunnels into the shell. 



• The sea cucumber has the 

 unique ability to throw out its entire 

 insides to deter an enemy. It can soon 

 grow a new set of internal organs. 

 The sea cucumber is a hollow sack 

 with a mouth bordered by 10 branch- 

 ing tentacles. When the animal is 

 feeding, the tentacles are extended. 

 When danger threatens, it first tries to 

 discourage a predator by contracting 

 its body and puckering up its mouth, 

 retracting the tentacles. 



These facts were adapted from 

 Nature Guide to the Carolina Coast, 

 written by Peter Meyer, and Seacoast 

 Life: An Ecological Guide to Natural 

 Seashore Communities in North 

 Carolina, written by Judith 

 Spitsbergen. 



Jeannie Faris 



22 JULY/AUGUST 1993 



