Crepidula dilatata Lamarck, 1822, truly living in the southwestern Atlantic

Volume: 45Start Page: 172End Page: 17

Gonadic cycle of Pseudechinus magellanicus (Philippi, 1857) (Echinoidea: Temnopleuridae) from Patagonia, Argentina

ZBSTRACT: Psettdecliirius tnagellanicus is one of the most abundant echinoids in Argentinean waters,r :cursing at depths from intertidal to over 150 m. It is distributed along the South American coast, from off Rioi- la Plata in the Atlantic Ocean, to Puerto Montt, in the Pacific Ocean. This species is also found in islands of7:: Antarctic Sea. It occupies a variety of habitats such as tide pools, mixed gravel and sand bottoms,'~crocystisb lades and Mytilus beds. Monthly samples were examined from September 2000 to March 2003.i?ecimens were collected by scuba diving from depths of 6-10 m in Golfo Nuevo, Puerto Mad~ynG. onad index- 2s analyzed monthly. There are two reproductive peaks and partial spawning events throughout the year. Major;-wnings were recorded in late winter (June-August) corresponding to the minimum winter water temperature.-9°C) and an increase in day length, and in summer (January- February), corresponding to the highest waters-aperature value (17-18OC) and maximum day lengths. These observations were corroborated by analysis-m'i croscopic changes in gonads and in the distribution of oocyte sizes in the ovary. Males recover faster-Y females, being able to spawn during ahnost the whole year. Resorption after spawning was observed in: -3 sexes. Oocytes bigger than 105 km have a jelly coat of 10-12 p,m which could protect them after released-I ::?e water

NEW RECORD OF CALYPTRAEID HOSTS FOR THE PEA CRAB CALYPTRAEOTHERES GARTHI (FENUCCI, 1975) (DECAPODA, PINNOTHERIDAE) IN ARGENTINA

Calyptraeotheres garthi (Fenucci, 1975) is one of nine species of Pinnotheridae occurring in Argentina and the only species of that genus located in this region. This species can be found from the San Maths Gulf, Argentina to Rio Grande do Sul, Brazil where it lives in symbiotic association with limpets of the family Calyptraeidae. Currently, two species of limpets have been reported as hosts of this species: Crepidula protea (d'Orbigny, 1841) and Crepidula argentina Simone, Pastorino & Penchaszadeh, 2000. We report here four more species of limpets serving as hosts of C. garthi, namely Bostrycapulus odites Collin, 2005, Crepidula cachimilla Cledon, Simone & Penchaszadeh, 2004, Crepidula plana Say, 1822 and Trochita pileus (Lamarck, 1822). Thus, this pinnotherid appears to be, as others members of the family, a generalist symbiotic species since it dwells on almost all the potential limpet species reported for Argentina. However, there are notable differences in prevalence of C. garthi on each host, which suggest that the symbiont might prefer species of Crepidula over the others genera (Trochita and Bostrycapulus). Additionally, there exists an apparent relationship between host size and prevalence (e.g., Crepidula cachimilla, the limpet with the highest prevalence, is clearly larger than the others hosts). Perhaps it is premature to conclude that the size of the host might be of benefit for the symbiont, but it is a hypothesis worthy of being explored.Universidad Nacional de Mar del PlataUniversidad Nacional de Mar del Plata [EXA 586/12]CONICET-Consejo Nacional de Investigaciones Cientificas y TecnicasCONICETConsejo Nacional de Investigaciones Cientificas y TecnicasCNPq-PDJ, Brazil [157489/2010-8]CNPqPDJ, Brazi

Trace Metal Residues in Marine Mussels: A Global Survey

Pressures from anthropogenic activities are causing degradation of estuarine and coastal ecosystems around the world. Trace metals are key pollutants that are released and can partition in a range of environmental compartments, to be ultimately accumulated in exposed biota. The level of pressure varies with locations and the range and intensity of anthropogenic activities. The present study measured residues of trace metals in Mytilus mussel species collected from a range of locations around the world in areas experiencing a gradient of anthropogenic pressures that we classified as low, moderate, or high impact. The data showed no grouping/impact level when sampling sites in all countries were incorporated in the analysis, but there was significant clustering/impact level for most countries. Overall, high-impact areas were characterized by elevated concentrations of zinc, lead, nickel, and arsenic, whereas copper and silver were detected at higher concentrations in medium-impact areas. Finally, whereas most metals were found at lower concentrations in areas classified as low impact, cadmium was typically elevated in these areas. The present study provides a unique snapshot of worldwide levels of coastal metal contamination through the use of Mytilus species, a well-established marine biomonitoring toolVersión del edito