Spatial distribution of symbiotic shrimps (Periclimenes holthuisi, P-brevicarpalis, Thor amboinensis) on the sea anemone Stichodactyla haddoni

This study investigated the spatial distribution patterns of three shrimp species, Periclimenes holthuisi, P. brevicarpalis, and Thor amboinensis on the sea anemone Stichodactyla haddoni in the laboratory. Anemones were partitioned into five zones (mouth, inner tentacle, outer tentacle, upper column, and lower column), and shrimp distribution on these zones was determined. Regardless of species, significantly higher numbers of shrimps chose outer tentacles (>40%) over other zones during daytime. Such distribution might be attributed to their feeding practices as these crustaceans clipped and ate parts of the outer tentacles. Periclimenes holthuisi also showed varying temporal distribution patterns on their hosts. At night when anemones contracted their tentacles, shrimp moved in significant numbers from the outer tentacle region either to the column or off the anemones. Shrimps returned to the tentacles during daytime when anemones expanded their tentacles. Thus, spatial and temporal distribution of shrimps depend upon their feeding activities and degree of anemone expansion.

First zoeal stage of the partner shrimp Periclimenes paivai Chace, with remarks on the genus Periclimenes OG Costa (Caridea, Palaemonidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CLEANER SHRIMP (CARIDEA: PALAEMONIDAE) ASSOCIATED WITH SCYPHOZOAN JELLYFISH

Shrimp are found in association with many hosts (sponges, anthozoans, mollusks, echinoids, ascidians and fish). Shrimp are rarely observed in association with jellyfish. The interaction between the cleaner shrimp Periclimenes paivai and jellyfish is poorly known, with only one published report for Brazilian waters. We add new information about this association, based on field and laboratory observations. Shrimp were collected from three locations on the coast Of Sao Paulo State (Cananeia, Santos and Sao Sebastiao) and from two species of scyphozoan rnedusae: Chrysaora lactea and Lychnorhiza lucerna. We classify the association as facultative commensalism, since the shrimp gain protection and probably feed on mucus produced by the jelly fish. The maximum carapace length of the shrimp collected was 9.2 min. Medusa bel I diameter ranged between about 10 and 19 cm for C. lactea and between 4.5 and 25 cm for L. lucerna. We also provide a list of records of Periclimenes in association with different scyphornedUsae, and additional information on the size and coloration of P. paivai.