Fig. 280.—Gambusia punctata, from Cuba. A. Male; B. Female.
Gambusia.—Cleft of the mouth developed laterally and horizontally. Snout not produced, with the lower jaw more or less prominent. Both jaws with a band of teeth, those of the outer series being strongest and conical. Scales rather large. Origin of the anal fin more or less in advance of that of the dorsal. Anal fin of the male modified into an intromittent organ and much advanced.
Eight species from the West Indies and the southern parts of South America.—Allied genera are the Central American Pseudoxiphophorus and Belonesox.
Anableps.—Head broad and depressed, with the supraorbital part very much raised. Body elongate, depressed anteriorly and compressed posteriorly. Cleft of the mouth horizontal, of moderate width, the mandible being short; upper jaw protractile. Both jaws armed with a band of villiform teeth, those of the outer series being largest and somewhat movable. The integuments of the eye are divided into an upper and lower portion by a dark-coloured transverse band of the conjunctiva; also the pupil is completely divided into two by a pair of lobes projecting from each side of the iris. Scales rather small or of moderate size. Dorsal and anal fins short, the former behind the latter. The anal fin of the male is modified into a thick and long scaly conical organ with an orifice at its extremity.
Three species from tropical America. They are the longest Cyprinodonts, attaining to the length of nearly twelve inches. Their peculiar habit of swimming with part of the head out of the water has been noticed above (p. 113).
II. Cyprinodontidæ Limnophagæ.—The bones of each ramus of the mandible are but loosely joined; intestinal tract with numerous circumvolutions. Sexes differentiated. Mud-eating. Tropical America.
Poecilia.—Cleft of the mouth small, transverse; mandible very short. Both jaws with a narrow band of minute teeth. Scales rather large. Origin of the anal fin generally nearly opposite to that of the dorsal fin in the female, but in the male it is modified into an intromittent organ and much advanced. Dorsal fin short, with not more than eleven rays.
Sixteen species.
Mollienesia.—Differing from Poecilia in having a larger dorsal fin, with twelve or more rays.