A first report on the shrimp Pontonia sp. and other potential symbionts in the mantle cavity of the penshell Pinna carnea in the Dominican Republic

Abstract

Examination of the mantle cavity of 310 penshells Pinna carnea, collected from seagrass beds in southwestern Dominican Republic, revealed the presence of four species from three phyla as potential symbionts. The shrimp Pontonia sp. was found in 178 penshells, the cardinalfish Astrapogon stellatus in 18, an anemone (order Actiniaria) in two, and a pea crab (family Pinnotheridae) in one. The penshell likely provides these organisms with a refuge from predators. It also provides nutrition for shrimp as they consumed food trapped in the mucus secreted by the penshell host. All of the cardinalfish, and 91% of the shrimp, were found in penshells measuring >150 mm in hinge length. At approximately 150 mm, the shells of P. carnea thicken and so flatten less when the valves are closed. As a result, larger penshells provide more mantlecavity space for accommodating organisms. Shrimp and cardinalfish size increased with the size of the host penshell. The positive relationship between shrimp size and penshell size, a prevalence of male-female pairs of shrimp and other field observations, suggest that a longterm association exists between shrimp and penshells, and that the mating system of the shrimp involves social monogamy.

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

“…In socially monogamous symbiotic crustaceans, the population distribution also 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]. Furthermore, there is often a tight correlation between the body size of male and female symbiotic individuals living in pairs and the body size of symbiotic individuals is tightly correlated with that of the host individuals harboring them [13,15,26,31].…”

The Sexual and Mating System of the Shrimp Odontonia katoi (Palaemonidae, Pontoniinae), a Symbiotic Guest of the Ascidian Polycarpa aurata in the Coral Triangle

“…This is in contrast to that reported for other socially monogamous crustaceans in which, (heterosexual) pairs are found in host individuals more frequently than expected by chance alone (e.g., Pontonia margarita : [ 11 ]; Pontonia sp . : [ 56 ]; Pontonia mexicana : [ 12 ]). Below, we discuss additional characteristics of the association between O .…”

“…On one hand, in agreement to that reported for other socially monogamous shrimps (e.g., Pontonia margarita : [ 11 ]; Pontonia sp . : [ 56 ]), males of O . katoi were, on average, smaller than females, and the major cheliped of males did not exhibit positive allometry.…”

Sexual and reproductive traits of the pearl oyster shrimp Pontonia margarita (Decapoda: Palemonidae), symbiotically inhabiting the mantle cavity of the rugose pen shell Pinna rugosa (Bivalvia: Pinnidae)

“…For example, Kennedy et al (2001) and Rada and Milat (2009) concluded that the association between Pontonia pinnophylax (Otto, 1821) and Pinna nobilis Linnaeus, 1758 represents commensalism, while Pacheco et al (2014) described a mutualistic relationship between the same shrimp species and the bivalve P. rudis Linnaeus, 1758. Symbiosis has been reported between several species of pontoniids and a wide range of host taxa including corals, jellyfish, sponges, and mollusks (Criales 1984, Morrison et al 2004, Baeza 2008, Baeza and Díaz-Valdés 2011, Baeza et al 2015. Bivalve hosts inhabited by small shrimp are one of the most studied models of symbiosis (Baeza 2008, Aucoin and Himmelman 2010, Baeza et al 2013. The morphological, sexual, and reproductive traits of decapods (Richardson et al 1997, Baeza 2008 in relation to host size (Baeza et al 2015) are important indicators used to infer the degree of symbiotic association between two species.…”