Short communication. Statolith microstructure from hatchlings of the oceanic squid, Gonatus onyx (Cephalopoda, Gonatidae) from the Northeast Pacific

Statolith microstructure was studied in hatchlings of deepwater-spawnedgonatid squid Gonatus onyx, caught between 1350 and1420 m over a bottom depth of 2100 m in the San Clemente Basin off SanDiego, California. It was found that the shape and size of the hatchlingstatolith were similar to those of the first-check statolith observed inparalarvae and small juveniles of G.onyx. The innerpart of the bipartite postnuclear zone (= first-check statolith) is formedduring late embryo-genesis, and the first check within the statolithmicrostructure must be considered as a starting point of increment countingfor age estimation of Gonatus spp.