368 



Abstract— Larval development of the 

 southern sea garfish (Hyporhamphus 

 melanochir) and the river garfish (H. 

 regularis) is described from specimens 

 from South Australian waters. Larvae 

 of H. melanochir and H. regularis 

 have completed notochord flexion at 

 hatching and are characterized by an 

 elongate body with distinct rows of 

 melanophores along the dorsal, lat- 

 eral, and ventral surfaces; a small to 

 moderate head; a heavily pigmented 

 and long straight gut; a persistent pre- 

 anal finfold; and an extended lower 

 jaw. Fin formation occurs in the follow- 

 ing sequence: caudal, dorsal and anal 

 (almost simultaneously), pectoral, and 

 pelvic. Despite the similarities between 

 both species and among hemiramphid 

 larvae in general, H. melanochir larvae 

 are distinguishable from H. regularis by 

 1) having 58-61 vertebrae I vs. 51-54 for 

 H. regularis); 2) having 12-15 melano- 

 phore pairs in longitudinal rows along 

 the dorsal margin between the head 

 and origin of the dorsal fin (vs. 19-22 

 fori/, regularis); and 3) the absence of a 

 large ventral pigment blotch anteriorly 

 on the gut and isthmus (present in H. 

 regularis). Both species can be distin- 

 guished from similar larvae of southern 

 Australia (other hemiramphids and a 

 scomberosocid ) by differences in mer- 

 istic counts and pigmentation. 



Larval development of the southern sea garfish 

 (Hyporhamphus melanochir) and 

 the river garfish U-l. regularis) 

 (Beloniformes: Hemiramphidae) 

 from South Australian waters 



Craig J. Noell 



Department of Environmental Biology 



Adelaide University 



Soutti Australia 5005 



Present address: SARDI Aquatic Sciences 

 PO Box 120 

 Henley Beach 

 South Australia 5022 



E-mail address: noell craigiffisaugovsa au 



Manuscript accepted 25 October 2002. 



Manuscript received 31 December 2002 

 at NMFS Scientific Publications Office. 



Fish. Bull. 101:368-376(20031. 



The beloniform family Hemiramphidae 

 (garfishes or halfbeaks) are small to 

 medium-size surface-dwelHng marine, 

 estuarine, and freshwater fishes. The 

 family contains 12 genera and 101 

 species worldwide, and more than one- 

 third of the species belong to the genus 

 Hyporhamphus (Froese and PaulyM. 

 The Hemiramphidae are related to 

 the Exocoetidae (flyingfishes) and, 

 more distantly, to the Scomberosocidae 

 (sauries), Belonidae (needlefishes), and 

 Adrianichthyidae (ricefishes) (Collette 

 et al., 1984). Six genera and 17 species 

 of hemiramphids occur in Australian 

 waters, where garfishes have long been 

 considered valuable food and bait fish 

 (Collette, 1974; Kailola et al., 1993). 



Two hemiramphid species inhabit 

 the waters of South Australia (S.A.), 

 namely the southern sea garfish Hypo- 

 rhamphus melanochir (Valenciennes, 

 1846) and the river garfish H. regularis 

 (Giinther, 1866). Adults of both are 

 widely distributed along southern Aus- 

 tralia from Western Australia (W.A.) to 

 New South Wales, although H. regula- 

 ris have not been recorded in Tasmania 

 (Tas.). They support important com- 

 mercial and recreational fisheries, par- 

 ticularly in S.A. (Kailola et al., 1993). H. 

 melanochir are commonly found in shel- 

 tered coastal waters, whereas H. regu- 

 laris are confined to estuaries (Jones 

 et al., 1996). Juveniles and adults of 

 both species co-occur in some estuaries 



of southern Australia, e.g. Port River- 

 Barker Inlet of S.A. (34°45'S, 138°31'E) 

 (Jones et al., 1996) and Peel-Harvey Es- 

 tuary of W.A. (32°32'S, 115°43'E) (Noell, 

 unpubl. data). 



Despite their widespread distribution 

 and economic importance, the early 

 life history of H. melanochir is only 

 partially described (i.e. reproductive 

 biology [Ling, 1958]; egg development 

 (Jordan et al., 1998], and there is no 

 published information for H. regularis. 

 Furthermore, although adults are eas- 

 ily identified with keys and descriptions 

 provided by Collette (1974), no such in- 

 formation exists for the larvae. A funda- 

 mental prerequisite for any larval fish 

 study is, undoubtedly, their accurate 

 identification (Neira et al., 1998). 



Thus far, at least some larval stages 

 have been described for 19 hemiram- 

 phids worldwide (Sudarsan, 1966; Tai- 

 wan 1967; Hardy 1978; Chen, 1988; Wat- 

 son, 1996; Prince Jeyaseelan, 1998), 

 eight of which belong to Hyporham- 

 phus. The purposes of this paper are 

 to describe the larval development of 

 H. melanochir and H. regularis and 

 to document distinguishing characters 

 between larvae of these species. 



' Froese, R, and D. Pauly 2001. FishBase. 

 World Wide Web electronic publication. 

 Accessed 28 Nov 2001. Web site: www.fish 

 base.org. 



