New Zealand Journal of Marine and Freshwater Research abstracts
Growth rates of five species of surf clams on a southern North Island
beach, New Zealand
H. JOHN CRANFIELD
KEITH P. MICHAEL
National Institute of Water & Atmospheric
Research Ltd
P. O. Box 14 901, Kilbirnie
Wellington, New Zealand
email: j.cranfield@niwa.cri.nz
Abstract Growth rates of five species of surf clam were
estimated on the Kapiti Coast, southern North Island, New Zealand.
Length-frequencies of sequential population samples were analysed by the
computer program, MULTIFAN. Incremental growth of marked individuals was
analysed by the computer program, GROTAG. The von Bertalanffy growth parameters
k and
L[[infinity]] estimated by MULTIFAN for
Spisula
aequilatera (Deshayes in Reeve, 1854) were 0.80 yr
-1 and
52.1 mm; for
Mactra murchisoni Deshayes in Reeve, 1854 were 0.60
yr
-1 and 72.3 mm; and for
M. discors Gray, 1837 were
0.35 yr
-1 and 60.1 mm. MULTIFAN could not model growth of
Paphies donacina (Spengler, 1793) and
Dosinia anus (Philippi,
1848) from the population samples. The growth parameters estimated by GROTAG
for
D. anus were 0.53 yr
-1 and 53.0 mm and for
M.
murchisoni 1.84 yr
-1 and 72.4 mm. The growth rates of
P.
donacina,
S. aequilatera, and
M. discors were estimated for
the size range of their incremental growth data and the estimates are usable
for this limited size range only. Growth rates of each species varied with
depth in the surf zone in the same way in the North and the South Island. The
growth rate of two species was faster in the South Island and asymptotic size
of all species was greater in the South Island.
Keywords surf clams; Kapiti Coast; growth; recruitment; von
Bertalanffy parameters; mark-recapture; length-frequency; Paphies
donacina; Spisula aequilatera; Mactra murchisoni; Mactra
discors; Dosinia anus; MULTIFAN; GROTAG
New Zealand Journal of Marine and Freshwater Research, 2001, Vol. 35
M01021
Received 5 March 2001; accepted 3 July 2001
PDF file of entire paper: medium quality (1221K); (scanned from paper original: notes about this process)
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