183 



Abstract — Morphological develop- 

 ment of the larvae and small juve- 

 niles of estuary perch {Macquaria 

 colonorum) 1 17 specimens, 4.8-13.5 

 mm body length) and Australian bass 

 (M. novemaculeata) (38 specimens, 

 3.3-14.1 mm) (Family Percichthyidae) 

 is described from channel-net and 

 beach-seine collections of both species, 

 and from reared larvae of M. novemac- 

 uleata. The larvae of both are charac- 

 terized by having 24-25 myomeres, a 

 large triangular gut (54-67% of BL) 

 in postflexion larvae, small spines 

 on the preopercle and interopercle, 

 a smooth supraocular ridge, a small 

 to moderate gap between the anus 

 and the origin of the anal fin, and 

 distinctive pigment patterns. The two 

 species can be distinguished most 

 easily by the different distribution 

 of their melanophores. The adults 

 spawn in estuaries and larvae are 

 presumed to remain in estuaries 

 before migrating to adult freshwa- 

 ter habitat. However, larvae of both 

 species were collected as they entered 

 a central New South Wales estuary 

 from the ocean on flood tides; such 

 transport may have consequences for 

 the dispersal of larvae among estuar- 

 ies. Larval morphology and published 

 genetic evidence supports a reconsid- 

 eration of the generic arrangement of 

 the four species currently placed in 

 the genus Macquaria. 



Larval development of estuary perch 

 (Macquaria colonorum) and Australian bass 

 (M novemaculeata) (Perciformes: Percichthyidae), 

 and comments on their life history 



Thomas Trnski 



Amanda C Hay 



Ichthyology. Australian Museum 



6 College Street 



Sydney, New South Wales 2010, Australia 



E-mail address (for T Trnski, senior author): tomt@austmus gov au 



D. Stewart Fielder 



New South Wales Fisheries 



Port Stephens Fisheries Centre 



Private Bag 1 



Nelson Bay, New South Wales 2315, Australia 



Manuscript submitted 20 November 2003 

 to the Scientific Editor's Office. 



Manuscript approved for publication 

 15 June 2004 by the Scientific Editor. 



Fish. Bull. 103:183-194 (2005). 



The Percichthyidae is a family of 

 freshwater fishes restricted to Aus- 

 tralia (8 genera, 17 species) and South 

 America (2 genera, 7 species) (John- 

 son, 1984; Nelson, 1994; Allen et al., 

 2002; Paxton et al., in press). There is 

 continuing debate regarding the mono- 

 phyly of the family; several genera are 

 variously allocated to separate fami- 

 lies: Gadopsis is allocated to Gadop- 

 sidae (Allen et al., 2002; see Johnson, 

 1984 for a history of the systematic 

 placement of the genus) and Edelia, 

 Nannatherina, and Nannoperca are 

 allocated to Nannopercidae (Allen et 

 al., 2002). Other Australian genera 

 of Percichthyidae include Bostockia, 

 Guyu, Maccullochella , and Macquaria 

 (Pusey and Kennard, 2001; Allen et 

 al., 2002; Paxton et al., in press). The 

 genera Percolates and Plectroplites 

 were synonymized with Macquaria, 

 based on morphological and biochemi- 

 cal characters (MacDonald, 1978), 

 and although this arrangement was 

 accepted by Paxton and Hanley (1989), 

 Paxton et al. (in press), Eschmeyer 

 (1998), Johnson (1984), and Nelson 

 (1994) recognized both Percolates and 

 Plectroplites as valid genera. 



There are four described species in 

 the genus Macquaria, all confined to 

 southeastern Australia. Macquaria 

 ambigua occurs naturally in fresh- 

 waters of the Murray-Darling river 



system and has been translocated 

 outside of its natural range (Kai- 

 lola et al., 1993; Allen et al., 2002). 

 There is genetic evidence for an ad- 

 ditional undescribed freshwater spe- 

 cies closely related to M. ambigua 

 from central Australian drainages 

 (Musyl and Keenan, 1992). Mac- 

 quaria australasica is also confined 

 to freshwater of the Murray-Darling 

 river system, and an isolated popu- 

 lation exists from the Shoalhaven 

 and Hawkesbury Rivers, New South 

 Wales (Allen et al„ 2002) that may be 

 a separate species (Dufty, 1986). The 

 other two species (M. colonorum and 

 M. novemaculeata) are catadromous 

 and occur in coastal southeastern 

 Australian drainages between south- 

 ern Queensland and eastern South 

 Australia (Paxton et al., in press). 

 They are sympatric from northern 

 New South Wales (NSW) to eastern 

 Victoria. Adults of M. novemaculeata 

 occur in freshwater, whereas M. colo- 

 norum prefers brackish water of estu- 

 aries (Williams, 1970). Both species 

 migrate to estuarine areas to breed 

 in winter (Allen et al., 2002). Both 

 species are protected from commer- 

 cial fishing but are highly prized by 

 recreational fishermen (Harris and 

 Rowland, 1996; Allen et al., 2002) 

 and M. novemaculeata is an impor- 

 tant aquaculture species. 



