Sex change and life history pattern in the shrimp thor manningi (decapoda: caridea): a novel case of partial protandric hermaphroditism

TLDR: A population of Thor manningi sampled for one year was composed of 50% primary males, 49% protandric hermaphrodites, and 1% primary females, with average life spans of approximately 4-5 months.

Abstract: A population of Thor manningi sampled for one year was composed of 50% primary males, 49% protandric hermaphrodites, and 1% primary females. Primary males have prehensile third pereiopods, massive appendices masculinae, and life-long sperm production. Protandric hermaphrodites pass first through a male phase (non-prehensile third pereiopods, small appendices masculinae, sperm production) and a transitional phase (reduction of appendices masculinae and sperm ducts, development of female incubatory flanges, ovarian development) before maturing into breeding (embryocarrying) females.Eighty-six to 100% of females (female-phase hermaphrodites and primary females) in monthly samples carried embryos. Breeding females produced new embryo clutches approximately every nine days. Although reproduction was continuous, recruitment chiefly occurred in the summer. Measurements of density, size-specific dry weight, and cohort analysis indicate average life spans of approximately 4-5 months, production of 35 mg dry weight...