Reference: Biol. Bull., 148: 219-242. (April, 1975) GONADAL DEVELOPMENT DURING THE ANNUAL REPRODUC-TIVE CYCLE OF COMANTHUS JAPONICA (ECHINODERMATA: CRINOIDEA) NICHOLAS D. HOLLAND, JOHN C. GRIMMER AND HIROSHI KUBOTA Division of Marine Biology, Scrips Institution of Oceanography, University of California at San Diego, La Jolla, California 92037 . and Misaki Marine Biological Station of the Uniz'ersity of Tokyo, Misaki, Kanagawa-ken, Japan Echinoderm gonads have been described from periodic histological examinations made throughout the annual reproductive cycle in the following classes : Holo-thuroidea (Tanaka, 1958); Ophiuroidea (Patent, 1969; Fenaux, 1970, 1972); Asteroidea (Pearse, 1965; Chia, 1968; Crump, 1971); and Echinoidea (Yoshida, 1952; Fuji, 1960; Holland and Giese, 1965; Holland, 1967; Fenaux, 1968; Pearse and Phillips, 1968; Holland and Holland, 1969; Holland and Rommel, 1969; Mc-Pherson, 1969; Pearse, 1969a, 1969b. 1970; Conor, 1973a, 1973b). No com-parable study has yet been published for any species of the echinoderm class Crinoidea. Therefore, the present investigation describes gonadal development during the annual reproductive cycle of Comanthus japonica (Miiller), an un-stalked crinoid. The anatomy and histology of the crinoid reproductive system are diagrammed in Figure 3 of Holland (1975). MATERIALS AND METHODS We studied a population of Comanthus japonica. living on rocks at the entrance of Koaziro Bay, Kanagawa Prefecture, Japan. At each collection we captured 3 to 25 adult crinoids by diving in a few meters of water. The distribution of male, female and unsexable animals was as follows: 14 December 1972 (1 M + 7 F) ; 1 March 1973 (3 M + 7 F) ; 7 May 1973 (5 M + 4 F) ; 1 July 1973 (3 M + 4 F) ; 4 August 1973 (5 M + 4 F) ; 18 August 1973 (5 M + 4 F) ; 2 September 1973 (2 M + 3 F) ; 15 September 1973 (3 F) ; 24 September 1973 (8 F) ; 27 September 1973 (14 F) ; 30 September 1973 (12 F) ; 2 October 1973 (3 M + 13 F) ; 7 October 1973 (4 M + 14 F) ; 11 October 1973 (13 M 4-12 F) ; 22 October 1973 (5 M + 4 F + 4 U) ; 8 November 1973 (4 M + 7 U) ; 24 November 1973 (2 F + 8 U) ; and 1 February 1974 (4 M + 6 F). For the samples of 15 September 1973 through 2 October 1973, we deliberately collected more females than males; however, for 14 December 1972 and 7 October 1973, the predominance of females over males was presumably due to random sampling error. The collected animals had 28 to 42 arms each and had disc diameters from 2.4 to 3.7 cm ; crinoids in this size range had presumably been through at least one annual reproductive cycle before our study commenced. On the day of collection, several genital pinnules were removed from each animal about a fifth of the way between the arm base and the arm tip ; they were fixed at once in sea water-Bouin's fluid. The fixation of 2 October 1973 was 219
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