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NATSUMI KANEKO¹, YOTA OSHIMA AND YUZURU IKEDA
Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa, 903–0213 Japan.
Email: k058554@eve.u-ryukyu.ac.jp (¹corresponding author)

Abstract

Egg brooding behavior and embryonic development of the tropical intertidal octopus, Octopus laqueus, were observed in captivity. Three females spawned eggs in captivity and cared for them until the juveniles hatched. Some eggs were reared separately in an incubator for observation. The eggs of O. laqueus are small (mean capsule length 2.6 ± 0.1 mm) and hatchlings are planktonic. Embryonic development of O. laqueus closely resembled that of other octopus species with planktonic young including two reversals of embryos, at stage VII or VIII and stage XIX. Although hatching of maternal reared eggs was observed from 22 to 30 days after eggs were spawned, more than 75 % of hatching occurred within one hour on the same day. When the eggs hatched the mother flushed them from the den by jetting water from her funnel. Hatchlings possess short arms (47% of mantle length) with three suckers per arm. They remain in the plankton for an unknown period of time as paralarvae.

Key words: tropical octopus, spawning, brooding and egg care, embryonic development

Full article (PDF; 220 KB)