. Cold-blooded vertebrates: part I. Fishes. Fishes; Amphibians; Reptiles. FISHES The blennies and blennylike fishes furnish cases in which the ventrals sometimes are completely wanting or greatly reduced in size. The common cuskeel (Risso/a marginata), of the South Atlantic coast of the United States, whose ventrals are reduced to long, forked organs attached at the throat, seems to use them as the sea robin uses its pectorals, namely as feelers (see Fig. 34). The fact that the cuskeel is a night prowler lends support to this view. It lies buried all day in the sand, into which it descends ver
. Cold-blooded vertebrates: part I. Fishes. Fishes; Amphibians; Reptiles. FISHES The blennies and blennylike fishes furnish cases in which the ventrals sometimes are completely wanting or greatly reduced in size. The common cuskeel (Risso/a marginata), of the South Atlantic coast of the United States, whose ventrals are reduced to long, forked organs attached at the throat, seems to use them as the sea robin uses its pectorals, namely as feelers (see Fig. 34). The fact that the cuskeel is a night prowler lends support to this view. It lies buried all day in the sand, into which it descends vertically, tail down, leaving its head just near enough to the surface to admit a current of water to flow over the gills. When night comes it leaves the sand in search of a livelihood. Some observers have reported that the cuskeel possesses luminescent spots by means of which it makes light, and it is true that the fish has a row of pale spots along the side which are suggestive of luminescent spots. Furthermore, ample evidence has been produced to show that similar spots in a related Pacific coast form are luminescent. Nevertheless, I have made many observations on the Atlantic cusk- eel without seeing the slightest indica- tion of luminescence, and I am of the opinion, therefore, that the feelerlike ventral fins are the chief organs by means of which the animal feels its way over the bottom to seek the small crus- taceans, fish, and other animals of suitable size upon which it feeds. The cuskeel apparently becomes aware of the presence of the animals constituting its food through the sense of touch, from a stimulation in the sensitive ven- tral fins. Then, under the cover of darkness, it seizes its unwary and probably sleeping prey and devours Fig. 21. Ventral view of goby, Gobioioma bosci, to show clinging disk formed by union of the two ventral fins 44. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabi
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Keywords: ., bookcentury1900, booksubj, booksubjectfishes, booksubjectreptiles
