Development and ecology of larvae of the monotypic Australian fish family Dinolestidae

Abstract

The development and seasonal distribution of larvae of Dinolestes lewini, the sole species of the endemic Australian family Dinolestidae, are described for the first time using larvae 1.88–14.13 mm in body length caught in south-eastern Australia. Larvae have a moderately deep body, 27–29 myomeres, a moderate to large head, a large mouth with prominent, early-forming premaxillary teeth, small to moderate preopercular spines, a coiled and compact gut, and are moderately pigmented. Notochord flexion takes place between 4.8 and 7.0 mm and transformation at a size >14 mm. Larvae closely resemble those of Apogonops (Acropomatidae), Pomatomus (Pomatomidae) and Scomber (Scombridae), genera that have been postulated to be related to Dinolestes, but can be distinguished using a combination of myomere and fin-ray counts, and pigmentation. Larvae have been caught in marine waters off central New South Wales between January and November, and off western Victoria in late January, at depths between 30 and 0 m and within 8 nautical miles of the coast. The limited data on larval occurrence in New South Wales indicate that D. lewini spawns over an extended period, with a peak in autumn/winter.