422 



ONTOGENY AND SYSTEMATICS OF FISHES-AHLSTROM SYMPOSIUM 



mids (and Anoplopoma) is similar to that in Scorpaenoidei with 

 the neural and hemal arches ossifying before the associated ver- 

 tebral centra. Vertebral counts are notably high (47-63). Head 

 spines are absent in larval Hexagrammos and Pleurogrammus 

 and extremely reduced in Ophiodon. with late-stage larvae de- 

 veloping 4 tiny preopercular spines. 



Anoplopomatidae (Fig. 224. Table ;07j. -Larvae of only Ano- 

 plopoma have been described and illustrated by Kobayashi (1957) 

 and Ahlstrom and Stevens (1976). Early development oi Ano- 

 plopoma is similar to that of the hexagrammids. Larvae hatch 

 at a large size (~ 9 mm NL) and development is gradual without 

 great changes in form. 



Larvae are slender and elongate with pointed snouts and long 

 guts. The distinctive pectoral fins with heavy distal pigmentation 

 are exceptionally large reaching nearly 33% SL late in the larval 

 period. Larvae are heavily pigmented with melanophores over 

 most of the head, gut and lateral surface of the body. 



As in hexagrammid larvae, ossification is delayed with the 

 neural and hemal arches ossifying before the associated vertebral 

 centra. Vertebral counts (61-66) are distinctively high. Pectoral 

 fin development is precocious. Head and preopercular spines 

 are absent. 



Oxylebius-Zaniolepis (Fig. 224).- Oxylebius and Zaniolepis are 

 sometimes included in the Hexagrammidae, but are herein treat- 

 ed separately because of the distinctiveness of their larvae from 

 hexagrammids (Washington and Richardson, MS; Kendall and 

 Vinter, 1984). Larvae of Oxylebius pict us and Zaniolepis sp. are 

 illustrated and described by Kendall and Vinter (1984). Larvae 

 hatch at a small size (2.5-5 mm NL), undergo notochord flexion 

 between 6 and 9 mm NL, and transform to a benthic juvenile 

 at about 1 5 mm SL. 



Oxylebius and Zaniolepis are relatively short and deep-bodied 

 with large, bulging guts and rounded snouts. Pectoral fins de- 

 velop early and are distinctively large and fan-shaped. Pigmen- 

 tation is heavy over the anterior half of the body in preflexion 

 larvae and increases over the postanal lateral body witb devel- 

 opment. Zaniolepis possesses characteristic snout pigment which 

 is absent in Oxylebius. The pectoral fins of both species are 

 densely pigmented. 



Head spination is well-developed with preopercular (5 spines 

 in Oxylebius; 6-7 in Zaniolepis), posttemporal and supraclei- 

 thral spines present. Zaniolepis larvae develop distinctive prick- 

 le-scales over most of the body by about 7 mm. 



Normanichthyidae (Fig. 225^. -Larvae of the monotypic Nor- 

 manichthys crockeri are illustrated and described by Balbontin 

 and Perez (1980). Hatching occurs at a small size (4.4 mm NL) 

 and flexion of the notochord occurs at 7 to 9 mm. Development 

 from hatching to the juvenile stage is gradual without great 

 change. 



Larvae are elongate and slender with short, coiled guts and 

 distinctive large pectoral fins. Pigmentation is restricted to the 



pectoral fins and the ventral midline extending from the isthmus 

 to the tail. In small larvae several large melanophores are pre- 

 sent on the dorsal midline. 



Distinctive features of larval development include: the ab- 

 sence of head and preopercular spines, delayed ossification, early 

 development of the pectoral fin, and presence of only 5 bran- 

 chiostegal rays. 



Comephoridae (Fig. 225).— The endemic comephorids of Lake 

 Baikal in Russia are reported to be viviparous (Chemyayev, 

 1971, 1975) and are bom at a relatively large size (8.2-9.4 mm) 

 but are not well developed. Flexion of the notochord occurs at 

 about 8.2 to 13 mm. Larvae develop very slowly with trans- 

 formation occurring 3 or 4 months after birth. 



Larvae are extremely slender and elongate with small heads 

 and very short coiled guts. Comephorids are quite different from 

 other cottoids morphologically and are blennioid in appearance. 

 Pigmentation is usually limited to the gut and sometimes in a 

 series along the postanal lateral midline. Four small preoper- 

 cular spines develop in late-stage larvae; other head spines are 

 absent. 



Cottocomephoridae (Fig. 225). — Larvae of seven genera of Lake 

 Baikal cottocomephorids have been described and illustrated 

 (Chemyayev, 1971, 1975. 1978, 1981; Taliev, 1955). Larvae 

 hatch at about 5 to 10 mm, and range from forms with large 

 yolk sacs and no fin development (e.g.. Paracottus) to well de- 

 veloped, postflexion forms with fins well developed (e.g., Ba- 

 trachocottus). Size at transformation varies from 9 to 20 mm. 

 Larvae are slender with moderately short guts and rounded 

 snouts, somewhat similar to freshwater cotlids (Coitus) in form. 

 Pigmentation is variable with melanistic pigmentation usually 

 present on the head, nape, gut and variously on the dorsal and 

 ventral midline. Melanophores are frequently present in a row 

 along the lateral midline near the tail tip. 



Larvae develop 4 small preopercular spines accompanied by 

 two spiny projections from an inner preopercular shelf Other 

 head spines are lacking. 



Cottidae (Figs. 226-231). — The taxonomic status of the family 

 Cottidae is controversial with the number of recognized families 

 ranging from 1 to 17 (see Washington and Richardson, MS). To 

 minimize confusion, and because there is no generally agreed 

 upon classification of this "family," we use the generic groupings 

 identified by Washington and Richardson (MS) for our discus- 

 sion of early life history information. Larvae are known for 28 

 of the 70+ cottid genera. A general overview of larval cottid 

 taxonomy is presented in Richardson and Washington (1980), 

 Richardson (1981a), Washington (1981) and Fahay (1983). 



Rhamphocottus (Fig. 226). — Larvae of this distinctive, mono- 

 typic species hatch at a relatively large size (6-7 mm NL). No- 

 tochord flexion occurs at 7 to 8 mm and transformation to a 



Fig. 229. Larvae of the Artedius Part A group (A-C) and the Couus group of cottids of Washington and Richardson (MS) (see Washington 

 et al., this volume). (A) .Artedius fenestralis. 9.9 mm SL (from Richardson and Washington, 1980. as .Artedius Type 2); (B) ClmocoUus acuticeps. 

 10.4 mm SL (from Washington, in prep.); (C) Oligocottus snyderi. 10.2 mm SL (from Washington, 1981); (D) Leptocottus armatus. 8.1 mm SL 

 (from Richardson and Washington, 1980); (E) Cottus asper. 8.2 mm SL (ibid.). 



