Evaluating the taxonomic status of the large sized Tricolia Risso, 1826 in the Northeast Atlantic and Mediterranean Sea.

Despite a long history of taxonomic studies on the genus Tricolia Risso, 1826, there is a shortfall on thorough systematic molecular reviews of the taxon from the NE Atlantic and Mediterranean coasts. Aiming to assess the genetic distinctness among morphospecies and the taxonomic status of currently accepted large sized species in these areas, we conducted a molecular phylogenetic analysis of the genus based on one mitochondrial (cox1) and two nuclear (28S and ITS2) markers. Seven Tricolia species were consistently retrieved in the analyses, including a new genetic lineage in the NE Atlantic designated as Tricolia sp. 1. Molecular analyses revealed that only one species, T. azorica, occurs in the NE Atlantic archipelagos. The sister taxa T. pullus (Mediterranean) and T. picta (NE Atlantic) should be classified as distinct species, instead of subspecies of the T. pullus group (sensu Gofas 1982). Tricolia miniata is also a complex of species in the Mediterranean and future studies across the distribution range are necessary to clarify its status.

Preliminary account on the bryozoans of the Alboran platform (Western Mediterranean), with description of two new species.

The Alboran platform, located in the Alboran Sea, is an area of high productivity due to the mixture of the Atlantic and Mediterranean waters, which produce an almost permanent upwelling in the region. It has been considered one of the main biodiversity hotspots in the Mediterranean Sea. Previous taxonomic studies on bryozoans carried out around the Alboran platform mentioned a total of 127 species collected at depths between 28 and 480 m. Here we report on four Indemares (Inventario y designacin de la Red Natura 2000 en reas marinas del Estado espaol) samples collected in 2011 and 2012 at depths between 95 and 120 m from a biogenic gravel bottom (i.e. small rocks and shells). Sixty-eight taxa belonging to 52 genera and 34 families were identified. Two species are proposed as new (Escharella similis n. sp. and Hemicyclopora admirabilis n. sp.), eight taxa were identified only to genus level although two of them (Chorizopora sp., Hippothoa sp.) are likely to be undescribed species, and one taxon only at family level. Among the species identified, 30 are new records for the Alboran platform, 13 are new records for the Alboran Sea, and Microporella funbio is recorded for the first time in the Mediterranean Sea. These results covered only a small part of the material sampled (4 out of 44 samples), which suggests that the number of bryozoan species in the Alboran platform is even higher, and also shows the importance of this area for bryodiversity.

Rissoidae gastropods of the outer continental shelf and slope off Galicia (NW Spain).

More than 5000 shells (more than half of them with soft tissues) belonging to the caenogastropod family Rissoidae have been found in samples from several expeditions carried out in the outer continental shelf and slope off Galicia (Northwest Spain) in the depth range 100-2700 m. They belong to 9 genera and 23 species, two of them described as new for science: Alvania candasae sp. nov. and Alvania xelae sp. nov. The most abundant species in the samples were Obtusella macilenta (Monterosato, 1880) and Alvania testae (Aradas & Maggiore, 1844), followed by Alvania cimicoides (Forbes, 1844), Alvania jeffreysi (Waller, 1864) and Gofasia thalassae (Bouchet & Warén, 1993) comb. nov., which is proposed to be assigned to the genus Gofasia instead of Frigidoalvania. Five of the species are typically from upper shelf of which only few empty shells were found (Alvania cancellata, Crisilla semistriata, Manzonia crassa, Onoba semicostata) and their presence in the samples studied was considered accidental. Taxonomic complexity involving the species Alvania electa (Monterosato, 1874), Pseudosetia amydralox Bouchet & Warén, 1993 and Pusillina inconspicua (Alder, 1844) are highlighted.

Spermcast mating with release of zygotes in the small dioecious bivalve Digitaria digitaria.

Digitaria digitaria, a small astartid usually less than 10 mm in length, has a non-brooding behaviour in spite of its limited space for gonad development. This species lives in highly unstable environments with strong currents, which represent a challenge for fertilization and larval settlement. The studied population of D. digitaria from the Strait of Gibraltar area was dioecious, with significant predominance of females and sexual dimorphism, where females are larger than males. The reproductive cycle is asynchronous throughout the year, without a resting period, but with successive partial spawning events. The presence of stored sperm in the suprabranchial chamber and inside the gonad of some females, together with the release of eggs along the dorsal axis of both gills, points to internal oocyte fertilization. Bacteriocytes were found in the female and male follicle walls, but no bacteria were observed inside any of the gametes. Digitaria digitaria could represent a "missing link" between spermcast mating bivalves with brooded offspring and bivalves with broadcast release of eggs and sperm. The small size, limiting the oocyte production, together with the unstable environment could represent evolutionary pressures towards sperm uptake in D. digitaria.

The magnitude of global marine species diversity.

BACKGROUND: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. RESULTS: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. CONCLUSIONS: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century.