Meeting Abstract

P3.127  Friday, Jan. 6  The absence of male features and functionality in the monotypic shrimp genus Lysmatella, a simultaneous hermaphrodite MURRAY, Kendall B.*; DEMKO, Alyssa M.; WARD, Bridget K.; DELILLO, Cynthia A.; BALAZADEH, Keyvan; BOURQUE, Bradford D.; RHYNE, Andrew L.; Roger Williams University; Roger Williams University; Roger Williams University; Roger Williams University; Roger Williams University; Roger Williams University; Roger Williams University; New England Aquarium kmurray742@g.rwu.edu

Protandric simultaneous hermaphroditism is ubiquitous in the caridean shrimp genus Lysmata. Lysmata have external morphology that is characteristic of caridean shrimp. The most common method of identifying male phase shrimp is the presence of the appendix masculina on the second pleopod. It has been well established that all members of this genus can undergo sex change from male to euhermorphodites, sometimes dependent on group size. Additionally, the male phase in Lysmata is functional, allowing for successful fertilization between hermaphrodites and primary males. Given results from recent molecular phylogenies Lysmatella, a sister genus to Lysmata, is also expected to be a simultaneous hermaphrodite. The objective of this study was to investigate and document the sexual system of this monotypic genus. To accomplish this, Lymatella prima were maintained in pairs, observed, and resultant larvae reared in the laboratory. Newly metamorphosed shrimp were separated into individual containers and observed for three months. Breeding experiments were also conducted between mature hermaphrodites and immature individuals. Live samples in addition to excuvaie were collected to document development from the juvenile form to adult. Results indicate that Lysmatella lack features common in Lysmata and immature individuals cannot successfully fertilize mature hermaphrodites. Therefore, it appears that there is no functional male phase present in this monotypic genus prior to maturation.