Reproduction and growth of the spiny lebbeid shrimp, Lebbeus groenlandicus (Fabricius, 1775) (Caridea, Hippolytidae) in the deep-water of the East Sea, Korea

Abstract

Reproduction and growth of the spiny lebbeid shrimp, Lebbeus groenlandicus (Fabricius, 1775) are investigated in the East Sea of Korea from January 2012 to April 2013. An understanding of the reproductive strategies of a species is critical for understanding its population dynamics and biogeographic patterns (Ramírez-Llodra, 2002). Deep sea species would not undergo the seasonal periodicities in breeding shown by their relatives in shallower water subject to annual change in water temperature, but, instead, breeding would take place year-round (Orton, 1920). Population parameters are necessary in order to understand the health of any fishery to determine appropriate management measures (Nwosu, 2008). The proportion of females was significantly greater than that of males (male:female ratio, 4.6:5.4). Females were predominant on larger class size than males. Significant differences on slopes of carapace length versus body weight linear regression between sexes indicate sex-specific differences in allometric growth. The gonadosomatic index (GSI) varied monthly, reaching a maximum in November 2012 (10.28) and a minimum in March 2013 (2.15). Monthly variations in the proportions of ovigerous females showed all months. The highest values of the GSI coincided with the breeding period of L. groenlandicus. There was significant difference between the mean GSI of females with non-eyed and eyed eggs, indicating that L. groenlandicus is a consecutive breeder. There was a significant correlation between carapace length and the number of eggs at early egg stages. There was significant difference in the slope of the regressions of carapace length versus the number of eggs between females carrying non-eyed and eyed egg stages, indicating that there was brood loss during the incubation period. Based on dry weights in early egg stages, reproductive output was determined 0.18±0.006. The von Bertalanffy growth function parameters were 〖CL〗_∞=38.80 mm,K=0.48 〖yr〗^(-1),C=0.5,WP=0.4 for males and 〖CL〗_∞=43.64 mm,K=0.41 〖yr〗^(-1),C=0.6,WP=0.6for females. The growth performance index (φ') is 2.86 for males and 2.89 for females. This study verified the biological characteristics of L. groenlandicus inhabiting the deep sea in the East Sea of Korea. The present study will help manage fisheries resources based on ecological parameters, which was provided from the study.