Morphological
development of the swim bladder in hatchery-reared striped trumpeter Latris
lineata
A.J. Trotter, P.M. Pankhurst, S.C.
Battaglene-2004
Journal of
Applied Ichthyology, 20(5):
395-401
Summary:
This study examined swim bladder
morphogenesis in three cohorts of striped trumpeter (Latris lineata),
a euphysoclist species with physostomous larvae. The swim bladder was first
discernible 1-2 days after hatching as an evagination on the dorsal
surface of the incipient digestive tract. It comprised a cluster of
mesenchymal cells surrounding an inner primordium of epithelial cells. At
mouth opening in larvae of 5.3 mm standard length (SL), the swim
bladder was noticeably enlarged. Histologically, the swim bladder lumen was
dilated and liquid filled. The pneumatic duct was first seen during the
dilation stage and the rete mirabile began forming among the connective
tissue surrounding the swim bladder. Initial swim bladder inflation occurred
on day 11 post-hatching in Cohort 1, at 14°C, and day 9 post-hatching, in
Cohorts 2 and 3, at 16°C. Histologically, the lumens of inflated swim
bladders were ellipsoid and the epithelium was squamous, except for cuboidal
gas gland cells at the anterio-ventral and anterio-lateral regions of the
swim bladder. During the initial inflation interval the pneumatic duct was
dilated in larvae both with and without swim bladder inflation. The
pneumatic duct began to regress in some larvae over 7.5 mm SL. The swim
bladder of striped trumpeter was similar to larvae of other altricial
perciform marine fish in respect to organ derivation, tissue
differentiation, luminal dilation and initial gaseous inflation. However,
variations, particularly the delay in initial swim bladder inflation until
after the start of feeding, were observed that could be fundamental to
problems encountered during larval rearing.
(Ludwig Institute for Cancer Research,
P.O. Box 2008, The Royal Melbourne Hospital, Melbourne, Victoria 3050,
Australia.
E-mail: andrew.trotter@ludwig.edu.au)