Suborders Icosteoidei,Gobiesocoidei, and Callionymoidei

Suborders Icosteoidei,Gobiesocoidei, and Callionymoidei

The monotypic suborder Icosteoidei and family Icosteidae contains the very peculiar North Pacific Ragfish, Icosteusaenigmaticus. Elliptical in shape and highly compressed,spineless, scaleless, without pelvic fins as an adult, and with a largely uncalcified cartilaginous skeleton, these 2 m longpelagic predators look like a free-swimming flat fish with alimp body. They are a reported favorite prey of sperm whales.

The suborder Gobiesocoidei contains 140 species, all in the clingfish family Gobiesocidae. Gobiesocids are a shallowwater to amphibious family of small marine fishes often found in high-energy wave zones. The pelvic fins are modify ed into a sucking disk, the body is depressed, the head is rounded and flattened, and the skin is smooth and scaleless(Fig. 15.23). They have a unique pectoral girdle and vertebral rib arrangement. A relative giant in the family, the 30 cm Chilean Sicyases sanguineus feeds on snails, barnacles, chitons, and other high intertidal prey as well as many kinds of algae, often preferring the wave-splashed supratidal region to more regularly inundated depths (or heights)(Paine & Palmer 1978). Its flesh is reputed to have aphrodisiacqualities.

Figure 15.23

A gobiesocid clingfish, Gobiesox lucayanus, from theWest Indies. From Briggs (1974), used with permissionof McGraw-Hill, Inc.

Two families make up the suborder Callionymoidei, the callionymid dragonets (182 species) and the poorly studied,deeper waterdraconettid slope dragonets (12 species). Dragonets are a chiefly marine family of small, shallow water fishes in the Indo-West Pacific. Some species are pale white and live over sand, whereas others associated with hard bottoms are quite colorful. The family includes apopular aquarium species, the green and orange mandarinfish or Splendid Dragonet, Synchiropus splendidus .

Figure 15.24

A Japanese goby, Pterogobius daimio. From Jordan(1905).