Population distribution, host-switching, and chemical sensing in the symbiotic shrimp Lysmata pederseni: implications for its mating system in a changing reef seascape

Abstract

Lysmata pederseni, a protandric simultaneously hermaphroditic shrimp that inhabits the tube sponge Callyspongia vaginalis, is monogamous in the central and southeastern Caribbean Sea. We tested the null hypothesis of monogamy in a northern Caribbean population. In the Florida Keys, shrimps did not inhabit host individuals in pairs with a frequency greater than expected by chance alone. Hermaphrodites inhabited sponges solitarily and often brooded embryos. Hermaphrodites do not store sperm and need to be inseminated shortly after molting to fertilize a new batch of eggs. Thus, males and/or other hermaphrodites are likely switching among host individuals in search of sexual partners. Field experiments demonstrated low shrimp host fidelity. Host residence time was *2 times shorter for males than for hermaphrodites. We inferred a polygynandrous mating system from L. pederseni from the Florida Keys, with male-role and young hermaphrodites often moving among sponges in search of older, more sedentary, female-role hermaphrodites. We expected shrimps to use water-borne chemical cues originating from conspecifics or sponges to locate sexual partners. Experiments demonstrated that shrimps were attracted to waterborne cues originating from sponges but not conspecifics. We have described the mating system of a reef-associated shrimp in a fast-pace shifting seascape increasingly dominated by sponges and vanishing stony corals. In the central and southeastern Caribbean Sea, with greater coral cover and lower sponge abundance than in the Florida Keys, the same species is monogamous. Whether or not similar shifts in the social organization of other coral reef-dwelling marine organisms are occurring due to contemporary changes in seascapes is a relevant topic that deserves further attention.

Lysmata arvoredensisnov. sp. a new species of shrimp from the south coast of Brazil with a key to species ofLysmata(Caridea: Lysmatidae) recorded in the southwestern Atlantic

“…The dichotomous keys either based on morphological traits or color patterns herein developed aim to support future ecological studies in the south-western Atlantic Ocean. Only a few in situ studies has explored the ecology of the genus Lysmata in the region although most species are often observed by scuba divers ( Baeza et al, 2016 ). The genus Lysmata exhibits remarkable disparity in terms of ecology, social behavior, and mating systems ( Chace, 1997 ; Rhyne & Lin, 2006 ; Baeza & Anker, 2008 ; Baeza et al, 2009 ; Baeza, 2010 ; Laubenheimer & Rhyne, 2010 ; Rhyne, Calado & Dos Santos, 2012 ; Baeza & Fuentes, 2013 ; Giraldes, Coelho Filho & Smyth, 2015 ).…”

Sexual Selection and Mixed Sex Expression: Adolescent Protandry, Phenotypic Tradeoffs and ‘Unconventional' Sex Allocation Estimates in a Protandric-Simultaneous Hermaphrodite

“…In these species, individuals consistently mature and reproduce initially as males and later in life, after attaining female function, turn to functional simultaneous hermaphrodites. Protandric simultaneous hermaphroditism has been experimentally confirmed in a polychaete worm (Premoli and Sella, 1995), a land snail (Tomiyama, 1996), a tunicate (Manriquez and Castilla, 2005), a symbiotic barnacle (Crisp, 1983) and marine shrimps belonging to the genera Lysmata, Exhippolysmata, and Parhippolyte (Baeza, 2009(Baeza, , 2013Braga et al, 2009;Baeza et al, 2016a). Protandric simultaneous hermaphroditism is also suspected in other taxa [e.g., fish, snails, barnacles (Ghiselin, 1969(Ghiselin, , 1974Fischer, 1981;Charnov, 1982Charnov, , 1987Policansky, 1982;Crisp, 1983;Michiels, 1998;Chaine and Angeloni, 2005)].…”

Reproductive output of the ornamental shrimp Lysmata vittata (Stimpson, 1860) (Decapoda: Caridea) in wild populations and under different maturation diets

“…Lysmata seticaudata (Risso 1816) (d'Udekem d'Acoz 2002) and Lysmata californica (Stimpson 1866) (Bauer and Newman 2004)) to those that live in breeding pairs in low densities (e.g. Lysmata grabhami (Gordon 1935) (Wirtz 1997) and Lysmata amboinensis (De Man 1888) (Fiedler 1998)); (2) the confirmation of protandric simultaneous hermaphroditism (PSH) in all species studied (Bauer 2006;Baeza et al 2009;Baeza 2013) with an early male-phase; (3) a varied sociobiology related to the adoption of different mating systems (monogamous or promiscuous, Baeza 2010; Baeza et al 2016) and other aspects of reproductive biology, such as brood size (number of eggs per brood) and frequency of spawning (interspawn interval in days) (Bauer 2005).…”