Table of Contents
The several members of the sculpin and sea raven tribe that are known from the Gulf of Maine are a homogeneous group, characterized by large spiny heads; very wide gill openings; very broad mouths; slender bodies; separate spiny and soft-rayed dorsal fins (united in some rare species); large fanlike pectorals but small caudals; and by ventrals that are reduced to three long rays. All of them, too, have a fashion of spreading the gill covers and of flattening the head when taken in the hand. They likewise produce grunting sounds, and some of them have the power of inflating themselves with air or water when they are molested. The only other Gulf of Maine fishes that resemble them in general form, are the sea robins (p. 467), the toadfish (p. 518), and the goosefish (p. 537). But the entire head of the sea robin is armed with bony plates, different from the soft-skinned head of a sculpin; in the toadfish the soft portion of the dorsal fin is many times as long as the spiny part (at most twice as long as the spiny part in a sculpin); and not only are the fins of the goosefish small and weak as compared with the present family, but its lower jaw projects far beyond the upper, and its mouth is full of very large pointed teeth, whereas in the sculpins the teeth are small and the upper and lower jaws are of approximately equal length.
The sculpin tribe, as a group, are egg-laying fishes.[58] Among the Arctic members of the family, including the genera Artediellus, Cottunculus, Gymnocanthus, and Icelus, the males have a long anal papilla, through which the urinary duct and the sperm ducts both pass. The supposition is that this serves as a copulating organ, fertilization taking place within the female, and the fertilized eggs being laid soon after.[59]
| KEY TO GULF OF MAINE SCULPINS AND SEA RAVENS | |||
|---|---|---|---|
| 1. | There is only one dorsal fin, the spiny and soft parts being continuous, one with the other | — | Arctic sculpin, p. 453 |
| There are two separate dorsal fins | 2 | ||
| 2. | The first dorsal fin is deeply notched between the spines; the lower jaw and the top of the head are adorned with fleshy tags | — | Sea raven, p. 454 |
| The first dorsal is not deeply notched between the spines; there are no fleshy tags about the head | 3 | ||
| 3. | The long spine on each cheek is branched at the tip | — | Staghorn sculpin, p. 452 |
| The long spine on each cheek is simple, not branched at the tip | 4 | ||
| 4. | The anal fin is long (25 rays); there is a series of bony plates along each side of the body | — | Mailed sculpin, p. 441 |
| The anal fin is short (14 rays or fewer); there are no bony plates along the sides of the body | 5 | ||
| 5. | The long spine on the cheek is hooked upward | — | Hook-eared sculpin, p. 440 |
| The long spine on the cheek is straight, not hooked | 6 | ||
| 6. | The longest (uppermost) cheek spine is four times as long as the one below it, and reaches back to the margin of the gill cover; all the head spines are very sharp | — | Longhorn sculpin, p. 449 |
| The uppermost cheek spine is not more than twice as long as the one below it, and does not reach more than about half way to the margin of the gill cover; the head spines are blunter | 7 | ||
| 7. | Total length more than 9 inches | — | Shorthorn sculpin, p. 445 |
| Total length less than 8 inches | 8 | ||
| 8. | Anal fin with 13 or 14 rays; the soft skin of each side of the throat is pierced by a minute pore close behind the lower part of the last gill arch | — | Shorthorn sculpin, young specimens, p. 446 |
| Anal fin with only 10 or 11 rays; sides of throat behind last gill arch have no pore | — | Grubby, p. 443 | |
[58] Eggs with embryos far advanced in development have been reported within the ovaries of female short horn sculpins (Myoxocephalus scorpius) from Finland (Nordquist, Svensk. Fiskeri Tidskr., year 6, 1899). But it is well established that this sculpin ordinarily lays eggs, as described below (p. 447).
[59] See Jensen and Volsøe (Danske Vidensk. Selskab. Biol. Meddel., vol. 21, No. 6, 1949, p. 18) for a detailed account of the anal papilla in Icelus.