Fig. 12.12 Anoplogaster, the fang-tooth or mother-in-law fish. This is one of the
instances of the extreme “cephalization” of the body and the extreme lengths of
piercing teeth, features which have evolved repeatedly in mid-water fishes.
(^) (Drawing from Woods & Sonoda 1973.)
Almost Everything Is Slower
(^) On the basis of a modest array of data, it appears that mid-water organisms are long-
lived and grow slowly. At least one tough mid-water animal is amenable to laboratory
rearing, the shrimp-like, red mysid Gnathophausia ingens. Childress and Price (1978)
produced a size–frequency diagram (Fig. 12.13) for the population of the Southern
California borderland region (San Clemente Basin). The stock has distinct and non-
overlapping size classes, which are the sizes of 11 successive instars after the young
leave the brood pouch (there are two instars in the brood pouch). All 13th instar
individuals are reproductive females with young in the pouch.
Fig. 12.13 Frequency distribution of carapace length in Gnathophausia ingens, a
deep-sea mysid, collected off Southern California. Each of 11 size modes represents a
life-history stage or instar. Advance from one to the next occurs at molting.
(^) (After Childress & Price 1978.)