RESUMEN

BACKGROUND: The Caribbean spiny lobster Panulirus argus is heavily fished throughout its Greater Caribbean and Gulf of Mexico distribution, suggesting a heightened susceptibility to a fisheries collapse. In 2017, a nemertean worm, Carcinonemertes conanobrieni was described from ovigerous females of P. argus in Florida, USA. A year later, the presence of the same egg predator was recorded along the southern Caribbean coast (Colombia). The effect of this egg predator on the reproductive performance, including fecundity, embryo mortality, and reproductive output, of its host is unknown. This study tested whether C. conanobrieni affects embryo mortality, fecundity, and reproductive output in brooding females of P. argus. RESULTS: Artisan fishers caught 90 ovigerous lobsters near Pueblo Viejo, Magdalena, Colombia. Each ovigerous female was examined for the presence/absence of the egg predator. Lobster egg mortality (%), fecundity (nº eggs female-1), and reproductive output (%) were estimated. Prevalence of C. conanobrieni in the studied population was 87.78%. The mean intensity of C. conanobrieni (all life stages) in the population was 11.68 (± 1.98) egg predators per brood mass sample. Infected females brooding late-stage embryos exhibited lower fecundity, lower reproductive performance values, and higher embryo mortality compared to infected females brooding early-stage embryos. Embryo stage and worm infection level negatively impacted fecundity and reproductive output. Worm infection level and the number of adult nemertean worms also negatively affected embryo mortality. CONCLUSIONS: These results demonstrate an adverse effect of C. conanobrieni on the reproductive performance of P. argus. The interactive impact of this egg predator, natural stressors, and anthropogenic stressors on individual P. argus reproductive performance could facilitate losses at large-scale fisheries levels.

RESUMEN

A new species Nipponemertes incainca is described from the intertidal zone of Santa Marta, Colombia. A new recent approach based on both morphological and molecular characters is applied for the description. The main characteristics of the species are: red color, head shield-shaped with a mid-dorsal cephalic ridge, furrows pre-cerebral inconspicuous with few faint ridges orthogonal to furrow axis, two irregular groups of eyespots situated at lateral margins in precerebral cephalic region, proboscis provided with papillae and 12 nerves, stylet smooth supported on an oval basis, and two pouches containing 3-4 accessory stylets each. The sequence of the COI gene was analyzed as an additional support for the new species.

RESUMEN

We sequenced the complete mitochondrial genome of the Heteronemertea species, Micrura ignea. The genome was amplified with a combination of short and long PCRs that were subjected to 454 sequencing. The mitogenome of M. ignea is a circular molecule of 15,333bp in size and encodes the 37 genes typically found in metazoans, and one non-coding region. The order of the genes is the same as for all the other Heteronemerteans. All genes are encoded on the heavy strand except trnT and trnP. The phylogenetic analyses recovered M. ignea as a basal taxon in the Lineidae family, no differences were found in the topology of the phylogenetic trees in comparison with previous studies.

Asunto(s)

Genoma Mitocondrial/genética , Invertebrados/genética , Animales , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa

RESUMEN

A checklist of benthic ribbon worm species from the Caribbean coast of Colombia is presented, including synonyms, distributions, a photographic record, and the main morphologic characters of each species for a rapid identification. This is the first research focused broadly on nemerteans in Colombia. 54 specimens of nemerteans were hand-collected from the rocky littoral of two different localities, and identified according to personal experience and specialist literature. 13 species were found; of which 11 represent new records for the country. These species belong to eight different traditionally used families: Tubulanidae, Valenciniidae, Lineidae, Amphiporidae, Cratenemertidae, Emplectonematidae, Drepanophoridae and Ototyphlonemertidae. The most common and abundant species was Dushia atra. The biodiversity of nemerteans in Colombia seems to overlap with the nemertean fauna from Florida and Brazil, explained by the convergence of the North Brazil Current, Guiana Current, Caribbean Currents and the Panama-Colombia Contracurrent in the sampled region. The results of this work suggest that the Caribbean coast of Colombia is a region with a high diversity of nemerteans, and provide important taxonomic data for environmental assessments and future biological research.