Histological Authentication of Reproductive Structures of Little Indian Squid Loliolus (Loliolus) hardwickei, Grey, 1849 (Cephalopoda: loliginidae)

Abstract

The work deals with the oogenesis, spermatogenesis and associated reproductive structures of the little Indian squid Loliolus (Loliolus) hardwickei. Histological descriptions of the ovary, oviduct, testis and needham sac were made, the various changes observed during maturation were described and the functional significance was discussed. The female reproductive system consists of the ovary, glandular oviduct, lace-like oviducal funnel, paired nidamental gland, accessory nidamental glands and a seminal receptacle for sperm storage on the ventral side of the buccal cavity. The average size of the cells of the ovary varied from 7.635±3.466 µm (primary oogonia) to 1191.114±288.188µm (Ripe oocyte). Oocyte resorption or the presence of atretic oocytes was observed in some sections. The male reproductive system consists of the testis, vas deferens, spermatophoric organ, spermduct, the system of spermatophoric glands (SG) and spermatophoric sac (Needham sac) and penis. The spermatogenesis passed through the differentiation of primodial germ cells, primary and secondary spermatogonia, primary and secondary spermatocytes, rounded spermatids, and elongated spermatids to spermatozoa or sperms. The testis is connected to a thin-walled Needham sac by the spermatophoric duct. The testis is made up of numerous seminiferous tubules and is enveloped by tunica albuginea made up of connective tissue. Histological authentication of reproductive structures in L(L) hardwickei serves the specific purpose of providing a detailed understanding of the species' reproductive biology, which has implications for ecological, environmental, and conservation management efforts.