New Zealand Journal of Marine and Freshwater Research abstracts
Visual assessment of the reproductive condition of female western rock
lobsters (Panulirus cygnus)
Roy Melville-Smith
Simon de Lestang
Western Australian Marine Research Laboratories
P.O. Box 20
North Beach
WA 6920, Australia
email: rmsmith@fish.wa.gov.au
Abstract An important issue when surveying the reproductive
condition of large numbers of female Panulirus cygnus in the field
is that each animal must be assessed quickly and accurately on the basis
of only a few easily discernable criteria. The four biological criteria most
commonly recorded for each lobster are: (1) ovigerous setae condition (not
present, partially developed, and fully developed); (2) the presence (unused
or eroded) of a spermatophore mass; (3) the presence and developmental stage
of external ova; and (4) the visual appearance of the ovaries through the
dorso-thoracic musculature. Using the above criteria each female can then
be assigned to a reproductive state, i.e., immature, inactive breeder, single
breeder, or double breeder. This study compared external assessments with
internal cellular development of the ovary (via histology) and elucidated
the shortcomings of the external technique. This has resulted in the production
of a modified set of criteria that, if applied to samples collected during
the peak of the breeding season, enables the breeding state of a female western
rock lobster to be more accurately determined in the field without causing
it any damage. The height of the breeding season is the optimum time for
stock egg production assessment.
Keywords lobster; Panulirus cygnus; visual assessment;
reproductive condition; double breeding
M04018; Online publication date 8 June 2005 Received 8 February 2004;
accepted 27 September 2004
New Zealand Journal of Marine and Freshwater Research, 2005, Vol. 39:
557-562
0028-8330/05/3903-0557 © The Royal Society of New Zealand 2005
PDF file of entire paper: Print-quality (234K) |
screen-quality (110K)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
