Larval development of estuary perch (Macquaria colonorum) and Australian bass (M. novemaculeata) (Perciformes: Percichthyidae), and comments on their life history

Morphological development of the larvae and small juveniles of estuary perch (Macquaria colonorum) (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. novemaculeata. The larvae of both are characterized 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 freshwater 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 estuaries. Larval morphology and published genetic evidence supports a reconsideration of the generic arrangement of the four species currently placed in the genus Macquaria.

Early life history of the Argentine sandperch Pseudopercis semifasciata (Pinguipedidae) off northern Patagonia

The Argentine sandperch Pseudopercis semifasciata (Pinguipedidae) sustains an important commercial and recreational fishery in the northern Patagonian gulfs of Argentina. We describe the morphological features of larvae and posttransition juveniles of P. semifasciata and analyze the abundance and distribution of early life-history stages obtained from 19 research cruises conducted on the Argentine shelf between 1978 and 2001. Pseudopercis semifasciata larvae were distinguished from other larvae by the modal number of myomeres (between 36 and 38), their elongated body, the size of their gut, and by osteological features of the neuro- and branchiocranium. Pseudopercis semifasciata and Pinguipes brasilianus (the other sympatric species of pinguipedid fishes) posttransition juveniles were distinguished by their head shape, pigmentation pattern, and by the number of spines of the dorsal fin (five in P. semifasciata and seven in P. brasilianus). The abundance and distribution of P. semifasciata at early stages indicate the existence of at least three offshore reproductive grounds between 42−43°S, 43−44°S, and 44−45°S, and a delayed spawning pulse in the southern stocks.

Age, Growth, Life History, and Fisheries of the Sand Sole, Psettichthys melanostictus

Sand sole, Psettichthys melanostictus, is a small but important part of the west coast groundfish fishery. It has never been assessed and there is a limited amount of biological data for the species. We provide the first estimates of age and growth for California populations and compare them with studies from other areas. We found that sand sole is a rapidly growing species which may show a strong latitudinal gradient in growth rate. We also found evidence of a recent, strong cohortrelated shift in the sex ratio of the population towards fewer females. In addition we examined data from the Washington, Oregon, and California commercial fishery to make an initial determination of population status. We found that catch per unit of effort in commercial trawls experienced a decline over time but has rebounded in recent years, except central California (the southern part of its commercial range), where the decline has not reversed.