Three decades of horseshoe crab rearing: a review of conditions for captive growth and survival

Abstract

AbstractThreats to wild horseshoe crab populations and growing interest in their use for research, education and biomedical applications have prompted demand for improved techniques to rear and maintain crabs in captivity. Although numerous laboratory studies have been conducted to determine growth and survival of horseshoe crabs under various conditions, these data have not been compiled and summarized to inform culture practices. We surveyed the literature and analysed the range of available techniques to identify and define a consistent set of conditions for maximum growth and survival of horseshoe crabs in culture. We considered three age classes; embryo, juvenile and adult, and included all extant species (Limulus polyphemus, Carcinoscorpius rotundicauda, Tachypleus gigas and Tachypleus tridentatus). We discovered relatively few published studies that clearly related husbandry conditions to growth and survival. Comparison among studies was complicated by inconsistent data collection and reporting techniques. Most published sources reported data for younger age classes, and more studies considered L. polyphemus than Asian species. The most commonly reported variables (temperature, salinity, enclosure maintenance and diet composition) showed size dependent and in some cases species‐specific effects on growth and survival that will be important in guiding culture efforts. We suggest that future studies give additional consideration to substrate type, water flow, dissolved oxygen concentrations, diet quality and the quantity and frequency of feeding. If laboratory‐reared stocks are to be used for propagation and restoration activities, future studies will benefit from closing these data gaps and promoting international data sharing.