Indian J. Fish., 37 (2): 169 -170 (1990) INCIDENCE OF PSEUDOHERMAPHRODITISM IN THE SPINY LOBSTER PANULIRUS HOMARUS (LINNAEUS) E. V. RADHAKRISHNAN*, M. VIJAYAKUMARAN** AND K. SHAHUL HAMEED** Central Marine Fisheries Research Institute, Cochin - 682 031, India ABSTRACT Specimens of the spiny lobster, Panulirus homarus ranging in size from 22.3 - 97.5 mm carapace length (67 - 245 mm total length) with well developed male genital system, but with biramous pleojxxls (as in females) were recorded in 1987,1988 and 1989 from trammel net catches off Kovalam, near Madras. The probable factors responsible for this sexual abnormality have been discussed. In March, 1987, while observing the Sexual abnormalities like gynandro- juvenile lobsters caught in the trammel net off morphism, bisexuality and hermaphroditism Kovalam near Madras, a few lobsters of though not common in lobsters, have been Panulirus homarus of size ranging from 22.3 - described in a few species, including Jasus 43.6 mm in carapace length (67 -122 mm in frontalis (Burger, 1902), Jasus lalandii (von total length) were found to have male genital Bonde, 1918; Hickman, 1945; Bradstock, 1949), system but biramous pleopods as in females Homarus americanus (Chace and Moore, 1959) instead of the normal uniramous pleopods and Nephrops norvegicus (Farmer, 1972). How­ (Fig. 1 A, B & C). In April of the same year, ever, there are only a few other examples of a lobster of same species measuring 97.5 mm 'pseudohermaphroditism' in lobsters, von in carapace length and 245 mm in total length Bonde (1937) described such a phenomenon with similar abnormality was recorded from in Jasus lalandii and Gordon (1957) noted the the same area. In 1987, out of 121 lobsters same anomaly in Homarus gammarus. This is examined, 14 numbers were found to have the first record of such a phenomenon from this anomaly. Subsequently, in 1988 and a tropical palinurid lobster. 1989 about 10% of the lobsters with abnormal pleopods were recorded. Five of the lobsters The biramous pleopods of the abnor­ with the abnormal pleopods were dissected mal specimens are unique in that but for their and the genital system examined. Neither very much reduced size, they structurally any abnormality in their genital apparatus resemble those of normal females. More­ nor any parasites were noticed. A squash over, the outer segment of the endopod of preparation from different parts of the testis pseudohermaphrodites are longer, whereas did not reveal presence of any ova. Since the the two segments are almost equal in length animals have morphologically similar genital in normal females (Fig. 1 B & C). While system as in males, excepting the biramous normal females have setae on both the seg­ nature of the pleopods, they were considered ments of the endopod, in pseudohermaph­ as functional males and this phenomenon, as rodites, only the outer segment of the endo­ 'pseudohermaphroditism', a type of non­ pod has setae. These abnormal specimens functional hermaphroditism. have been reafed in the laboratory and the Present address: • Regional Centre of CMFRI, Mandapam Camp, India. "Madras Research Centre of CMFRI, Madras, India. NiJTE REFEKENCSS BRAi}srocK, C. A. 1949. N. Z. Set. Rev., 7 (5) : 69. BURCIW, O. 1902. Zeitsdirift Wissenschaftl. Z«,>Ic)gk'. 71 ; 702^707. CiiACK, E. A. JR. ANDM. MOOIE 1959. Biol. Bull, 116; 226- 2.11. CifARNiAim - CotTON, 11. AND G. PAYEN 1985. In : The Biakigy of Crustacea, Vol, 9 D. E. Bll.ii,s (Ed.), pp. 217^ 28.3, Academic Pres.s, New York. FARMER. A. S. 1972. Mar. Biol. 1.5 ; 344^'M9. Ckmmm, I. 1957. AMTL Mag. Nat. lUst, (12) 15 : 524-,528. LIICKMAN, V. V. 1945. Pap, Proc. R. S(K. Tmmmm, 1944 : S7''S9. REIDENBACH, J. M. 1967. C r, hebd. Sane. Acad. ScL Paris. 2.65 :1321^..1323. VON Bomm, C. 1918. Trans. R. Soc. S. Afr., 7 (.5) : 69. VON FJONDIV C 1937. .5. Afr. J. .Sal, .13 : 827-832. 170 .