José E F Alfaya

Instituto de Biología de Organismos Marinos (IBIOMAR-CONICET) · Laboratorio de Reproducción y Biología Integrativa de Invertebrados Marinos (LARBIM)

The implementation of molecular data for the analysis of nemertean diversity has unraveled the taxonomic status of several species and many higher taxa within the group. Nowadays, a large proportion of novel putative species are being discovered and it is necessary to add molecular data to the morphological description to obtain a correct identific...

Climate change has consequences over marine organisms and their behavior. Echinoderms have been found to be negatively affected on righting time, survival, feeding rate or growth by high temperatures, low salinity or their interaction. We analyzed the effects of temperature and salinity fluctuation under a climate change scenario on feeding rate, r...

The nemertean Malacobdella arrokeana is a commensal of the edible giant bivalve Panopea abbreviata; both species have a restricted geographic distribution, high specificity and populations settled along distinct biogeographic provinces. This supposes a high genetic structuring among populations and low intra-populational variability; nevertheless,...

High densities of the invasive sea slug, Pleurobranchaea maculata, have been detected on the Argentinean coast, but studies on the species’ adaptation have been absent until now. Stomach contents of P. maculata in two sampling sites located at Golfo Nuevo, Patagonia Argentina, revealed animals as a major prey, but surprisingly algae ingestion on bo...

Heteronemerteans, such as Lineus ruber, L. viridis, Ramphogordius sanguineus, R. lacteus, Riseriellus occultus, and Micrura varicolor, share many similar external characters. Although several internal characters useful for distinguishing these nemertean species have been documented, their identification is based mostly on coloration, the shape of t...

We examined trophic relationship between the nemertean Malacobdella arrokeana and its host, the edible geoduck Panopea abbreviata by studying the diets of both species by direct (stomach contents) and indirect methods (stable-isotope analysis of C and N). In addition to these methods, the feeding behavior of M. arrokeana within the host and the mor...

Nemerteans of the genus Malacobdella live inside of the mantle cavity of marine bivalves. The genus currently contains only six species, five of which are host-specific and usually found in a single host species, while the sixth species, M. grossa, has a wide host range and has been found in 27 different bivalve species to date. The main challenge...

The taxonomy and anatomy of the southwestern Atlantic geoduck, Panopea abbreviata Valenciennes, 1839, are revised. Materials from several institutions, as well as new living specimens collected from the coast of Argentina were studied. Type materials of all related nominal species are illustrated. The shell morphology, shell ultrastructure, hinge,...

The use of the DNA barcoding has been shown as a useful tool in order to estimate their actual biodiversity and to solve several taxonomical problems, but its potential is hindered by the fact that only 6% of the known nemertean biodiversity has been molecularly examined. Furthermore, many of the COI sequences available are not identified at specie...

Microsatellite loci (26 in total) were isolated for the first time for the entocommensal nemertean Malacobdella arrokeana, using 454 GS-FLX Titanium pyrosequencing. We developed conditions for amplifying these markers in 8 multiplex and 5 individual reactions. One to 14 alleles were detected per locus across 25 samples analyzed from San Matı´as Gul...

Based on recent biodiversity studies carried out in different parts of the Mediterranean, the following 19 species are included as new records on the floral or faunal lists of the relevant ecosystems: the green algae Penicillus capitatus (Maltese waters); the nemertean Amphiporus allucens (Iberian Peninsula, Spain); the salp Salpa maxima (Syria); t...

The rocky shore of Punta Este, Golfo Nuevo (Patagonia, Argentina), was sampled by means of the standardized NaGISA (CoML) protocol, that was aimed to generate biodiversity baseline data in six levels, from high intertidal to 10 m depth. Based on the generated data, we analysed the benthic assemblage structure, species richness, mean abundance and t...

Malacobdella arrokeana is an entocommensal nemertean exclusively found in the bivalve geoduck Panopea abbreviata, and it is the only representative of the genus in the southern hemisphere. To characterize its genetic diversity, population structure and recent demographic history, we conducted the first genetic survey on this species, using sequence...

This article documents the addition of 83 microsatellite marker loci and 96 pairs of single-nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Bembidion lampros, Inimicus japonicus, Lymnaea stagnalis, Panopea abbreviata, Pentadesma butyracea, Sycoscapter hirti...

The yellow clam Mesodesma mactroides (Bivalvia: Mesodesmatidae) was once the most abundant intertidal species on the Atlantic coast of northern Argentina and an important commercial resource in South America. This study of a population inhabiting the intertidal zone of the sheltered-dissipative sandy beach Santa Teresita documents the species’ popu...

Growth rates of Mesodesma mactroides were estimated comparing two different methods at the intertidal of the exposed sandy beach Santa Teresita, Argentina. Results of a short tagging-recapture experiment using the in situ fluorescent marking (MFI) method and subsequent sizeincrement analysis were compared with results from lengthfrequency distribut...

The reproductive cycle and gonad development of the yellow clam Mesodesma mactroides was studied over a period of 24months (January 2005–December 2006) at the Argentinean sandy beach Santa Teresita. Histological examination of gonadal tissue revealed that sex ratios did not significantly deviate from the proportion of 1:1 and no case of hermaphrodi...

Growth rates of Mesodesma mactroides were estimated comparing two different methods at the intertidal of the exposed sandy beach Santa Teresita, Argentina. Results of a short tagging-recapture experiment using the in situ fluorescent marking (MFI) method and subsequent size-increment analysis were compared with results from length-frequency distrib...