Latin American Journal of Aquatic Research E-ISSN: 0718-560X [email protected] Pontificia Universidad Católica de Valparaíso Chile Miranda, Ivana; Mantelatto, Fernando Temporal dynamic of the relationship between the parasitic isopod Aporobopyrus curtatus (Crustacea: Isopoda: Bopyridae) and the anomuran crab Petrolisthes armatus (Crustacea: Decapoda: Porcellanidae) in southern Brazil Latin American Journal of Aquatic Research, vol. 38, núm. 2, julio, 2010, pp. 210-217 Pontificia Universidad Católica de Valparaíso Valparaiso, Chile Disponible en: http://www.redalyc.org/articulo.oa?id=175015266005 Cómo citar el artículo Número completo Sistema de Información Científica Más información del artículo Red de Revistas Científicas de América Latina, el Caribe, España y Portugal Página de la revista en redalyc.org Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Lat. Am. J. Aquat. Res., 38(2): 210-217, 2010 Lat. Am. J. Aquat. Res. 210 DOI: 10.3856/vol38-issue2-fulltext-5 Research Article Temporal dynamic of the relationship between the parasitic isopod Aporobopyrus curtatus (Crustacea: Isopoda: Bopyridae) and the anomuran crab Petrolisthes armatus (Crustacea: Decapoda: Porcellanidae) in southern Brazil Ivana Miranda1 & Fernando Mantelatto1 1Laboratory of Bioecology and Crustacean Systematics, Postgraduate Program in Comparative Biology Department of Biology, Faculty of Philosophy, Science and Letters of Ribeirão Preto University of São Paulo, CEP 14040-901, Ribeirão Preto (SP), Brazil ABSTRACT. The prevalence of the parasite Aporobopyrus curtatus in Petrolisthes armatus from southern Brazil was determined, and the effect the parasite had on host reproduction was evaluated. Of all 775 crabs sampled in Araçá region from March 2005 to July 2006, 3.2% presented bopyrid parasites. All the parasitized individuals had one branchial chamber occupied by two mature parasites, with no preference for the right or left chamber. Male and female hosts were infested in equal proportions. Parasitized juveniles, large individuals and ovigerous females were not found in our study. The absence of parasitized ovigerous females seems to be insufficient evidence to support the hypothesis of parasitic castration and would require a histological study to confirm their reproductive death. The percentage of infestation observed in our study (3.1%) is lower than the one found in other studies and it could indicate the existence of factor(s) regulating the density of A. curtatus in the Araçá region. At least in this population, the low but constant presence of the bopyrid A. curtatus population did not appear to have a negative effect on the porcellanid population, and parasitized individuals did not play a significant role in the natural history of P. armatus. Keywords: parasitism, castration, porcelain crab, southern Brazil, Atlantic Ocean. Dinámica temporal en la relación entre el isópodo parásito Aporobopyrus curtatus (Crustacea: Isopoda: Bopyridae) y el cangrejo anomuro Petrolisthes armatus (Crustacea: Decapoda: Porcellanidae) en el sur de Brasil RESUMEN. Se determinó la prevalencia del parásito Aporobopyrus curtatus en Petrolisthes armatus en el sur de Brasil y se evaluó el efecto de su presencia en la reproducción de su huésped. De marzo de 2005 a julio de 2007 se muestreó en la Region de Araçá un total de 775 cangrejos, de los cuales el 3,2% presentó bopíridos parásitos. Todos los individuos parasitados presentaron una cámara branquial ocupada por dos parásitos maduros, sin preferencia por la cámara derecha o izquierda. Machos y hembras hospedadores fueron infectados en la misma proporción. La ausencia de parásitos en hembras ovígeras no es evidencia suficiente para apoyar la hipótesis de castración parasítica, y se necesita un estudio histológico para confirmar la muerte reproductiva. El porcentaje de infectación observado (3,1%) es inferior al encontrado en otros estudios y puede ser indicativo de la existencia de factor(es) que regulan la densidad de A. curtatus en la region de Araçá. En conclusión, estos resultados sugieren que, al menos en esta población, la baja y constante incidencia del bopírido A. curtatus parece no afectar la población del porcelánido, y los individuos parasitados no tienen un papel significativo en la historia natural de P. armatus. Palabras clave: parasitismo, castración, cangrejo de porcelana, sur de Brasil, océano Atlántico. ________________________ Corresponding author: Fernando Mantelatto ([email protected]) 211 Interaction by bopyrid in Petrolisthes armatus in southern Brasil INTRODUCTION present (Bonnier, 1900). This hypothesis was revised and after studies showed that, even parasitized, some Parasites are exploitative organisms that typically take host individuals are still able to molt and reproduce, nutrients and energy from their hosts, and perhaps although less frequently and efficiently (Van Wyk, benefit from transport, protection and a thermally 1982; O’Brien & Van Wyk, 1985). regulated environment provided by the host’s body According to Letitia et al. (2000), there exists no (Barnard, 1990). Bopyrid isopods are obligate general pattern among arthropods, but the specific parasites, most commonly found on the gills and/or biology of hosts and parasites may produce biases one abdomen of decapod hosts, which may be castrated way or the other in some host-parasite species (Van Wyk, 1982; O’Brien & Van Wyk, 1985). The combinations. Members of the genus Aporobopyrus Bopyridae (sensu stricto, not included Entoniscidae Nobili, 1906 are branchial-chamber parasites of and Dajidae) is the most speciose and best studied anomuran crabs of the family Porcellanidae, e.g. family of epicaridean parasites of decapod hosts, with Pachycheles rudis (Stimpson, 1859; Van Wyk, 1982), 595 described species distributed worldwide and a Petrolisthes armatus (Gibbes, 1850; Oliveira & large number of species underreported (Markham, Masunari, 1998), Petrolisthes politus (Gray, 1830; 2003; Boyko & Williams, 2009). Scelzo, 1985) and Porcellana sayana (Leach, 1820; These isopods require two host species to complete A. Meireles, pers. com.), shrimps of the families their life cycle and the definitive host is a decapod Hippolytidae (Calado et al., 2005; Román-Contreras crustacean (Cheng, 1968). The female parasite & Romero-Rodríguez, 2005; Terossi & Mantelatto, produces broods of eggs that leave the marsupium as 2010) and Palaemonidae (Beck, 1979; Cash & Bauer, epicaridium larvae, a free-swimming stage with 1993), and brachyuran crabs (Jordá & Roccatagliata, sucking mouthparts. This larva searches for a free- 2002). living planktonic copepod, to which it attaches and The species of the Brazilian coast are poorly undergoes successive molts, to reach the microniscium investigated and only Aporobopyrus curtatus larval stage and cryptoniscus larval stage (the former Richardson, 1904 is known to infest the porcellanid is attached to the copepod, the latter moves off to seek crabs Petrolisthes armatus (Oliveira & Masunari, out a definitive host) (O’Brien & Cheng, 1968; Beck, 1998, 2006), P. galathinus (Bosc, 1802), P. 1979; Van Wyk, 1985). Cryptoniscus larvae are marginatus Stimpson, 1859, Pachycheles ackleianus sexually undifferentiated and adapted to a planktonic A. Milne-Edwards, 1880, P. greeleyi (Rathbun, 1900) phase, during which the isopod searches for the and Porcellana sayana (see Markham, 1975 and definitive host. Sexual differentiation of the newly Lima, 1978 for review). settled isopod (bopyridium) is dependent on the We evaluated the presence and possible presence or absence of another parasite attached to the interference effect of A. curtatus on a population of P. host. If the host is unparasitized, cryptoniscus larva armatus in southeastern Brazil. Patterns observed that will become a female bopyridium. If the host were compared with previously studied members of already harbors a parasite, the cryptoniscus larva the family Porcellanidae, in order to detect any becomes a male and attaches itself to the female's variability in the effects of these parasites on the life body (Reinhard, 1949; Lima, 1978; O’Brien & Van cycle of their hosts. Wyk, 1985). Typically, the definitive host will shelter only one bopyrid female per gill chamber, followed by one or more dwarf males (O’Brien & Van Wyk, MATERIAL AND METHODS 1985). Pardo et al. (1998) described an exception to this pattern for the galatheid Pleuroncodes monodon, a Specimens sampling protocol case in which many females were found parasitizing The Araçá region (23º48’78.1’’S, 45º24’46.9’’W) is a one individual. human impacted remnant mangrove area located near The effects of parasitism on the growth and the São Sebastião Channel on the northern coast of reproduction of the hosts are explored in the literature São Paulo. The effects of human and industrial (Van Wyk, 1982; O’Brien & Van Wyk, 1985; Somers impacts are easily seen in this area (see Vergamini & & Kirkwood, 1991), although the mechanisms through Mantelatto, 2008 for review). which parasites influence the molt cycles and Porcellanid crabs were collected by two people by reproduction of their hosts are still unknown (Van hand at two-month intervals in the Araçá region from Wyk, 1982). The first investigators of this subject March 2005 to July 2006, in a rocky intertidal area believed that the molt cycle of decapods was limited near the waterline. Specimens were collected under to a short period of the host's life when a parasite was rocks at low tide for 1 h and 30 min. This Lat. Am. J. Aquat.