Investigating temporal variation in stable carbon and nitrogen isotope values of Florida Caribbean spiny lobster (Panulirus argus) recruits

Abstract

The limited information available on the recruitment dynamics of the Caribbean spiny lobster, Panulirus argus (Latreille, 1804), has long been an issue for biologists. The long pelagic larval stage and the surface circulation in the Caribbean Sea have led many researchers to hypothesize that Caribbean lobster stocks are demographically open, implying connectivity among stocks in this region. Multiple approaches have been applied to investigate potential stock connectivity in this species, including biophysical modeling and genetic markers. Stable isotope analysis has proven to be a useful tool to study animal movement, and has been widely applied in studies of both terrestrial and aquatic species. However, this method has never been applied to Caribbean spiny lobster recruits. In the present study, we performed carbon and nitrogen stable isotope analyses on three sub-stages of the non-feeding pueruli (clear, semi-pigmented, and pigmented), as well as on the feeding, first juvenile stage that settled in the Florida Keys from August 2014 to July 2016. Results indicated that the stable isotope values differed between the feeding and non-feeding stages. The δ13C and δ15N values of the lunar monthly samples displayed notable temporal variation and oscillated during the 2-yr sampling period. Cluster analyses of the stable isotope values suggested that four clusters could have contributed to the observed Florida recruits. The results of our study reveal the possibility that the Florida spiny lobster stock receives recruits from multiple source populations outside Florida in addition to self-recruitment.