Early development of the endangered Oxleyan pygmy perch Nannoperca oxleyana Whitley (Percichthyidae) James T. Knight1, 2, * and Thomas Trnski3 1 Department of Industrial Investment NSW, Locked Bag 1 Nelson Bay, NSW 2315, Australia 2 School of Environmental Science and Management, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia 3 Marine Biology, Auckland War Memorial Museum, Private Bag 92018, Auckland, New Zealand * Corresponding Author: Tel: +61-2- 4916-3852, Fax: +61-2-4982-2265. Downloaded from http://meridian.allenpress.com/australian-zoologist/article-pdf/35/3/895/1477879/az_2011_044.pdf by guest on 24 September 2021 Email address:
[email protected] The developmental ontogeny and morphology of the eggs, larvae and early juveniles of the endangered Nannoperca oxleyana is described based on collections of preserved wild fish, and preserved and live captive specimens reared at 25 ± 1º C. Eggs are telolecithal, spherical, average 1.02 ± 0.004 (± S.E.) mm in diameter, have a smooth, slightly adhesive chorion without filaments, a translucent homogeneous yolk, display meroblastic cell division and follow the general pattern of teleost embryogenesis. Early, middle and late stages of embryonic development were completed on average at 16, 28 and 50 hours post fertilisation. The larvae have generalised perciform morphological development with no apparent larval specialisations. The body is moderately deep bodied and compressed laterally. Head spination is limited to the development of an opercular spine in postflexion larvae. Pigmentation is relatively heavy and uniform over the head and body. Large melanophores occur on the dorsal, lateral and ventral midlines. Squamation commenced in postflexion larvae from 7.5 mm preserved body length (BL) and was complete in all specimens greater than 10.3 mm.