Gonad development in the commercially exploited deepwater shrimp Solenocera agassizii (Decapoda: Solenoceridae) from Pacific Costa Rica, Central America

Commercial fisheries are going deep and the lack of life history data of the exploited deepwater species is considered a major limitation for the development and implementation of adequate management measures. Solenocera agassizii is a deepwater shrimp commercially exploited along the Pacific coast of Costa Rica; however, its reproductive biology is completely unknown. Therefore, this study was conducted to describe the ovarian development of this solenocerid species to facilitate the development of urgently needed management plans. Based on the relationship between macroscopic (color and ovary size) and microscopic (cell type) characteristics, four stages of ovarian development were determined (immature, previtellogenic, vitellogenic and mature) for the females of S. agassizii. A reabsorbing/spent ovary was not found. The four stages found can be grouped in “not visible” and “visible” based on the observation of the ovary through the exoskeleton in fresh specimens. These specimens can easily be used for a simple and rapid assessment of the gonad development in the field. Oocyte diameters ranged from 56.2 μm (Stage I) to 255.4 μm (Stage IV), and GSI (Gonadosomatic index) values varied between 0.36% (Stage I) and 6.65% (Stage IV). The classification obtained in this study was supported by coefficient of variance values and significant differences among stages, oocyte diameters and GSI values during the ovarian development. Therefore, we are confident that the combination of microscopic and macroscopic characteristics allows the establishment of easily recognizable developmental stages of the gonad in S. agassizii, which may be an important tool for future monitoring of the reproductive status of the population.

Research highlights
► We relate the macroscopic and microscopic (cell types) characteristics of the ovaries of Solenocera agassizii.
► We determine four stages of ovarian development (immature, previtellogenic, vitellogenic and mature). Reabsoring/spent ovary was not found.
► Stages can be grouped in “not visible” and “visible”, that can be used easily for a simple and rapid assessment of the gonad development in the field.
► The descriptions made are an important tool for future monitoring studies.