Host-use pattern of the shrimp Periclimenes paivai on the scyphozoan jellyfish Lychnorhiza lucerna: probing for territoriality and inferring its mating system

J Antonio Baeza,Samara De Paiva Barros-Alves,Douglas Fernandes Rodrigues Alves,Rudá Amorim Lucena,Silvio Felipe Barbosa Lima

doi:10.1186/s10152-017-0497-8

Abstract

In symbiotic crustaceans, host-use patterns vary broadly. Some species inhabit host individuals solitarily, other species live in heterosexual pairs, and even other species live in aggregations. This disparity in host-use patterns coupled with considerable differences in host ecology provide opportunities to explore how environmental conditions affect animal behavior. In this study, we explored whether or not symbiotic crustaceans inhabiting relatively large and structurally complex host species live in aggregations. We expected Periclimenes paivai, a small caridean shrimp that lives among the tentacles of the large and morphologically complex scyphozoan jellyfish Lychnorhiza lucerna, to live in groups given that the host traits above constraint host-monopolization behaviors by symbiotic crustaceans. We described the population distribution of P. paivai during a bloom of L. lucerna near the mouth of the Paraíba River estuary in Paraíba, Brazil. The population distribution of P. paivai did not differ statistically from a random Poisson distribution. Male shrimps were most often found dwelling on the surface of L. lucerna individuals as small groups (2–4 individuals), in agreement with expectations. Periclimenes paivai is a sexually dimorphic species with males attaining smaller average body sizes than females and exhibiting no elaborated weaponry (claws). Females, but not males, experience positive allometry in cheliped size and were found living solitarily in small but not large host individuals. The above suggest that females might be territorial or that they might be competing for resources (i.e., food) likely expected to impact their reproductive output. Our results agree, but only partially, with the idea that large and morphologically complex host species should harbor non-territorial gregarious symbiotic crustaceans. Symbiotic crustaceans represent excellent models to improve our understanding about the conditions driving the social behavior of marine organisms.

Highlights

Members belonging to the infraorder Decapoda, a specious clade of crustaceans [1, 2], develop symbiotic associations with a wide variety of invertebrate and vertebrate hosts, including poriferans, Baeza et al Helgol Mar Res (2017) 71:17Holthuis & Eibl-Eibesfeldt, 1964 [16], Petrolisthes mitra (Dana, 1852) [17], Thor amboinensis (De Man, 1888) [18]
Population distribution of Periclimenes paivai We examined the host use pattern of P. paivai, which includes a description of its population distribution, male–female association pattern, and host–shrimp body size relationships
In socially monogamous symbiotic crustaceans, the population distribution differs from a random Poisson distribution and host individuals harbor male–female pairs of symbiotic crustaceans either invariably [56] or with a frequency much greater than expected by chance alone [15, 26, 31, 57]

Summary

Introduction

Members belonging to the infraorder Decapoda, a specious clade of crustaceans [1, 2], develop symbiotic associations (symbiosis here defined sensu [3] as dissimilar organisms living together) with a wide variety of invertebrate and vertebrate hosts, including poriferans, Baeza et al Helgol Mar Res (2017) 71:17Holthuis & Eibl-Eibesfeldt, 1964 [16], Petrolisthes mitra (Dana, 1852) [17], Thor amboinensis (De Man, 1888) [18]. Theoretical and empirical studies suggest that host traits (e.g., abundance, body size, and morphological complexity: [27, 28]), predation risk off hosts [28], interspecific competition for hosts [29], and the host’s nutritional value [21] are relevant in explaining the diversity of host use patterns exhibited by symbiotic crustaceans. Baeza & Thiel [27] suggested that symbiotic crustaceans should live solitarily or in heterosexual pairs in or on their hosts when the host species is scarce, small (relative to the body size of symbionts), and morphologically simple [27, 28]. Baeza and Thiel [27] suggested that symbiotic crustaceans should not be territorial but instead live in aggregations when inhabiting host species reaching high natural abundance and exhibiting complex morphologies and large relative body sizes. The probability of symbiotic crustaceans exhibiting host-resource monopolization behavior is expected to decrease with increasing host abundance, host morphological complexity, and relative host size [5, 6, 27]

Methods

Results

Conclusion