HOUDE: CALLIONYMIDAE 



639 



sex characteristics and body size. Meristics also vary among 

 species (Table 169). In Nakabo's classification the genus Cal- 

 lionvimis includes only five species, all of which are fiaund in 

 the northeast Atlantic, Mediterranean or Black seas. Nakabo 

 (1982b) assigned 39 species to the Indo-Pacific genus Repo- 

 mucemts. making it the most species-nch genus of Callionym- 

 idae, followed by the Indo-Pacific genus Calliurichthys with 16 

 species. Neither eggs nor larvae were described or discussed by 

 Nakabo m his systematic account of the Callionymidae. 



Description 



The Callionymidae are characterized by having a small, pore- 

 like gill opening, greatly reduced in size compared to that of 

 Draconettidae, their closest relatives in the Gobiesociformes. 

 The preoperculum has a strong, often serrate, spine, useful for 

 specific identifications; the operculum and suboperculum are 

 spineless. Eyes are dorsal and adjacent. Hypurals are fused into 

 a single plate. Vertebrae number 21 to 23. Dorsal fin spines 

 usually four; soft rays 6-13; anal fin with 4-13 soft rays. Pelvic 

 fins are inserted in advance of the pectoral base, the two fins 

 often connected at their bases by a membrane. The sexes usually 

 are dimorphic, males having longer and broader median fins, 

 sometimes with filamentous rays in the dorsal and caudal fins. 



Development 

 Size at maturity varies among species but generally is less 

 than 100 mm. Some species may mature at < 15 mm in length 

 (Davis, 1966). Callionymid male-female pairs exhibit well-de- 

 fined courtship and spawning behavior (Wilson, 1978; Takita 

 and Okamoto, 1979) m which male display plays a prominent 

 role. Individual females may spawn on successive days. Judging 

 from larval occurrences, spawning seasons are protracted, last- 

 ing 6 months or more for temperate species such as C. lyra. C. 

 maculatus and C. reticulatus (Demir, 1972; Russell, 1976). 

 Spawning may occur year-round in subtropical species such as 

 C. pauciradiatus (Houde and Alpem Lovdal, in press) and Par- 

 acallionymus coslatus (Brownell, 1979) or tropical species such 

 as C. decoratus (Watson and Leis, 1974). 



Eggs 



Eggs are colorless, pelagic and spherical, reported diameters 

 ranging from 0.55 to 0.97 mm (Mito, 1962a; Watson and Leis, 

 1974; Russell, 1976; Brownell, 1979; Miller et al., 1979; Takai 

 and Yoshioka. 1979; Takita, 1980, 1983). A polygonal (usually 

 hexagonal) sculpturing, sometimes with fine cilia-like processes, 

 usually is associated with the chorion, but in some species (e.g., 

 P. costatus) the chorion apparently is unsculptured (Brownell, 

 1979). Buoyant, adhesive egg masses have been described for 

 C. calliste. which break up into individual pelagic eggs prior 

 to hatching (Takita, 1983). The yolk is segmented peripherally. 

 The perivitelline space is narrow. There are no oil globules. 

 Takai and Yoshioka (1979) and Takita (1980) have provided 

 good illustrations and photographs of typical callionymid eggs. 



Larvae 



At hatching, pelagic larvae of callionymids range from ap- 

 proximately 1 .0 to 2. 1 mm in length. Most species are less than 

 1.5 mm at hatching, making them among the smallest of larval 

 fishes. Reported myomere numbers range from 19-22. Callio- 

 nymid larvae are distinctive and easy to recognize. Larvae of 

 several species (referred to as Callionymus) have been described 

 (e.g.. Page, 1918; Mito, 1962a; Demir, 1972, 1976; Miller et al., 

 1979; Takai and Yoshioka, 1979; Takita, 1980, 1983). Brownell 



(1979) has illustrated larvae of Paracallionymus coslatus. All 

 larvae described to date are similar, differing in pigmentation 

 patterns, meristic characters and sizes at which fin development 

 and metamorphosis are completed. 



Yolk-sac larvae are short and deep-bodied with a large, bul- 

 bous yolk sac (Mito, 1962a; Brownell, 1979; Takita, 1980, 1983). 

 The yolk is segmented peripherally. Dendritic or stellate me- 

 lanophores may develop in the finfold (Fig. 340B) within one 

 day after hatching (Mito, 1962a; Brownell, 1979; Takai and 

 Yoshioka, 1979; Takita, 1980, 1983). The snout-to-anus length 

 of newly-hatched larvae is >50% of notochord length, but it 

 declines to <50% within several hours after hatching. 



Preflexion larvae are moderately deep-bodied and laterally 

 compressed both preanally and postanally. All species described 

 to date have a broken line of melanophores along the lateral 

 midline, particulariy on the tail (Fig. 340). The larvae are mod- 

 erately to heavily pigmented and often are first recognized in 

 samples because of their relatively dark color. A swimbladder 

 which develops at this stage subsequently is lost during meta- 

 morphosis. Curious processes, termed "spine-like" by Takita 

 ( 1 980, 1 983) or called "serrations" by Mito ( 1 962a) develop at 

 the margins of the dorsal and ventral finfolds (Fig. 340A), which 

 apparently vary in number among individual larvae. Takita 



( 1 980) described and illustrated a "vacuole" in the dorsal finfold 

 of small, preflexion larvae of C. flagris. C. richardsoni and C. 

 ornalipinnts. Multiple vacuoles were reported in the finfolds of 

 C. ca/fa/f (Takita, 1983). 



Postflexion larvae are heavily pigmented and robust (Fig. 

 340C). They have a prominent and highly visible, upturned 

 notochord tip (urostyle). Caudal, pelvic, second dorsal and anal 

 fin ray counts may be complete in some species at 3-4 mm SL 

 (Miller et al., 1979; Takai and Yoshioka, 1979). The head be- 

 comes flatter and broader as development progresses and the 

 eyes gradually assume their dorsal, adjacent position. The pre- 

 opercular spine first appears in the length range 3.5 to 5.0 mm 

 SL. For most species, size at metamorphosis is approximately 

 10 mm SL. 



Relationships 



Callionymid eggs and larvae offer little clue to systematic 

 relationships among gobiesociform fishes. Like the gobiesocids, 

 callionymid larvae are heavily pigmented (Allen, this volume) 

 but there are few additional similarities. Callionymid larvae 

 hatch from pelagic eggs; gobiesocids have demersal eggs. From 



Fig. 340. Larvae of Callionymidae: (A) 1.7 mm larva of Callionymus (Paradiplogrammus) calliste (from Takita, 1983: fig. 21, p. 443); (B) 4.7 

 mm larva of Callwnvmus reticulatus (from Demir. 1972: fig. 2. p. 998); (C) 4.1 mm lar\'a of Callionymus (Repomucenus) beniteguri {from Takai 

 and Yoshioka, 1979: fig. 2-4, p. 150); (D) 2.9 mm larva of Callionymus (Calliurichthys) decoratus (from Miller et al., 1979: fig. 96, p. 96); and 

 (E) 2.3 mm larva of Paracallionymus costatus (from Brownell, 1979: fig. 69, p. 50). 



