Abstract
The spiny lobster Panulirus homarus, distributed along the Southeast and Southwest coasts of India, is an important commercial species having mariculture potential. Despite its importance, the structural and ultrastructure features of male gonads from this species have received scarce attention. Hence this study was aimed to describe the male reproductive tract of the species, using standard histological and electron microscopy techniques. Gonads from 94 specimens of P. homarus ranging in carapace length 37mm-92mm from Vizhinjam (Southwest coast of India.) were obtained and processed for the study (Histology-70 numbers & ultrastructure-24 numbers). The male reproductive system consists of paired testis and vas deferens located in the cephalo-thoracic region. Macroscopically, the reproductive tract was observed in lobsters > 35mm carapace length. In immature testis, spermatogonia were seen which measured 6.9-13.8 microm in diameter and in the mature testis primary (5.4-5.9 microm) and secondary spermatocytes (2.8-3 microm) and spermatids (2.2-2.4 microm) were present. Each vas deferens consists of proximal and distal portions. The spermatophoric mass begins formation in the proximal vas deferens. In the distal vas deferens the spermatophoric mass containing the spermatozoa are arranged in packets towards the periphery by the gelatinous matrix produced by the typhlosole. Ultrastructurally, the spermatogonia have lamina, nucleus and mitochondria like bodies, the primary spermatocytes have nucleus, dense chromatin and vacuolated cytoplasm and the spermatids have mitochondria, endoplasmic reticulum and centrioles. The endoplasmic reticulum and the nuclear envelope in the spermatids form the acrosome. The radial arms with microtubules are formed in association with the dense endoplasmic reticulum, near the nucleus. The sperm has a spherical structure with the nucleus, lamellar region, spikes and acrosome. This is the first comprehensive report of the structure of the male gametes and spermatogenesis in P. homarus from Indian waters.
Highlights
Spiny lobsters are one of the world’s most valued and highly prized seafood and they support a large commercial fishery in many parts of the world
The present work describes in detail the histology and ultrastructure of the male reproductive tract which may lead to a better understanding of development of male gonads of the species, and permit creation of baseline information for further studies on reproductive biology
Morphological features of reproductive tract: The male reproductive system located in the cephalo-thoracic region consists of paired testis and vas deferens (Fig. 1A)
Summary
Spiny lobsters are one of the world’s most valued and highly prized seafood and they support a large commercial fishery in many parts of the world. They inhabit the temperate and tropical seas, but majority of the species and the highest abundance are found in the tropics (Holthuis, 1991). Panulirus homarus Linnaeus, 1758 is an important commercial spiny lobster species in India, found at a depth between 20-90m. The present work describes in detail the histology and ultrastructure of the male reproductive tract which may lead to a better understanding of development of male gonads of the species, and permit creation of baseline information for further studies on reproductive biology
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
