| Graveldiver | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Scytalinidae |
| Genus: | Scytalina |
| Species: | S. cerdale |
| Binomial name | |
| Scytalina cerdale Jordan & Gilbert, 1880 |
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The Graveldivers (Scytalina cerdale) are perciform fish in the genus Scytalina, and the only species in the family Scytalinidae.[1] Graveldivers are small, with a snake-like head (hence the generic name). The body is compact, and lacks pelvic fins, with very small pectoral fins. Their range encompasses the coastal area from the Bering Sea to central California.
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The generic name Scytalina is of a Greek origin, from the diminutive of skytale, meaning "viper".[2] This refers to the snake-like head. The specific name cerdale means "wary one" or "the fox", in allusion to its agility and quick movement when disturbed.[2] Jordan and Gilbert suggested an alternative generic name Scytaliscus due to the similarity between Scytalina and the unrelated genus Scytalinus. This name is unnecessary and is not in wide use.[2]
Graveldivers are small fish, reaching lengths of only 15 centimetres (5.9 in),[1] but usually not exceeding 10 centimetres (3.9 in).[2] They are long and compressed, resembling blennies.[3] The head is snake-like, earning it the generic name Scytalina. The dorsal fins and anal fins have no soft rays, and are supported only by thin spines.[2] Each has 41–51 spines, originating deep in the skin. They are at opposite sides of the body.[2] The dorsal and anal fins converge at the rounded caudal fin. The pectoral fins are very small, with only about eight rays, and the pelvic fins and girdle are absent altogether.[2] Gravedivers have no lateral line, scales, pyloric caeca, or swim bladder. They are pinkish-brown in colour, and may bear some purple markings. The edge of the caudal (tail) fin is reddish-orange.[2]
Graveldivers are marine fish found in the cold northern and eastern Pacific Ocean, from the Bering sea on the Alaskan coast to Diablo Cave in central California.[1] They are demersal fish, occurring in tidal pools and rocky bottoms. They may burrow under rocks and substrates such as sand, gravel, and broken shells, hence their name.[1][2] They may burrow to depths of 25 feet (7.6 m) or more.[4] Graveldivers generally inhabit shallow intertidal and subtidal areas.[2]