Dka. Barnes et Ls. Peck, AN ANTARCTIC SHELF POPULATION OF THE DEEP-SEA, PACIFIC BRACHIOPOD NEORHYNCHIA-STREBELI, Journal of the Marine Biological Association of the United Kingdom, 77(2), 1997, pp. 399-407
Thirty-five specimens of the articulate brachiopod Neorhynchia strebel
i were collected from a site at 814 m in the Weddell Sea. This was onl
y the second species of the order Rhynchonellida to be found in Antarc
tica. Formerly N. strebeli was known solely from abyssal Pacific Ocean
localities. A circumantarctic distribution is suggested in addition t
o the known deep-sea Pacific range. The specimens of this collection s
howed considerable commissure variation, suggesting that the previousl
y proposed erection of two subspecies on the basis of this character i
s erroneous, and emphasises the phenotypic plasticity of some articula
te brachiopods. The valve lengths and the number of alpha growth rings
in the sample showed a normal distribution and a von Bertalanffy grow
th function was fitted to the data: L-t = 23 (1-exp[-0.228t]). If the
alpha growth rings were of annual periodicity, the ages attained by th
e Antarctic N. strebeli of 11 y would be substantially lower than thos
e reported for other Weddell Sea brachiopods. The epibiotic communitie
s occurring on the valves of N. strebeli were impoverished, which is c
haracteristic of deep water Antarctic brachiopods. The few specimens c
ollected with their substratum were attached to small pebbles, but the
typical attachment substrata may be different.