Egg-jelly production, composition and function in oviparous elasmobranch species

Whereas live-bearing elasmobranch reproduction has been extensively studied, there is still a lack of knowledge concerning the importance of female investment in oviparous reproduction. In this study, the egg-jelly production, composition and function of oviparous elasmobranch species has been investigated in order to complete the larger picture of elasmobranchs intriguing reproductive diversity. Histological analysis on Scyliorhinus canicula and Raja Clavata has demonstrated that two zones are responsible for the egg-jelly production, confirming the presence of neutral and acid glycoprotein in zone A1 and strongly sulphated acidic mucins in zone A2. The secretory process of the egg-jelly demonstrated the secretion of a complex mixture made of diffusive secretions containing inclusions. In turn, the chemical analysis performed on Scyliorhinus canicula, Raja Clavata and Scyliorhinus stellaris revealed that the egg-jelly is a very hydrated material, containing proteins, lipids, minerals and carbohydrates. Conclusions concerning its possible function are still being examined. As a whole, this study surely participated in a better understanding of the female reproductive biology of oviparous elasmobranchs and lead to interesting discoveries.

Promotor(s) & Supervisor: Aaron Henderson
Thesis Institute: Galway-Mayo Institute of Technology

ISCED Categories

The highlighted icons, represent the fields of education (in compliance with ISCED Classification) engaged during this course/programme.

0521 - Ecology", "0511 - Biology