Babosas de mar psicodélicas: observaciones sobre la ontogenia del color en dos especies de nudibranquios del género Nembrotha (Doridina: Polyceridae)

In recent decades, thanks to the use of integrated taxonomy, the traditional recognition of a nudibranch species based on observation and colour pattern variation has become increasingly questioned, mainly due to the presence of cryptic and pseudocryptic species complexes. Individuals with the same colour pattern can be genetically identical, but individuals with different colour patterns may also be genetically identical and this variation may instead represent different life stages. But things can get even more complicated. What happens when the same species changes its colour pattern radically as it ages? Here we present two extraordinary examples in species of the genus Nembrotha based on laboratory observation. Specimens of Nembrotha livingstonei Allan, 1933 and Nembrotha yonowae Goethel and Debelius, 1992 were collected in Mozambique and kept in captivity as long as feeding was possible. The results showed that colour patterns in both species changed over time and that this change was linked to diet. Furthermore, species delimitation analysis and comparison of the uncorrected COI pairwise distances of examined specimens from Mozambique and others downloaded from GenBank confirmed that N. yonowae Goether and Debelius, 1992 is a junior synonym of N. cristata Bergh, 1877. Similar studies with laboratory observations are needed on other species of the genus, as they were described on the basis of different colouration, but integrated taxonomy may show different results.En las últimas décadas, gracias al uso de la taxonomía integrada, el reconocimiento tradicional de una especie basado en la observación y la variación del patrón de color en los nudibranquios se ha vuelto cada vez más cuestionado, principalmente debido a la presencia de complejos de especies crípticas y pseudocrípticas. Por lo tanto, los individuos con el mismo patrón de color pueden ser genéticamente idénticos, pero los individuos con diferentes patrones de color también pueden ser genéticamente idénticos y, en cambio, esta variación puede representar diferentes etapas de la vida. Pero las cosas pueden complicarse aún más. ¿Qué sucede cuando la misma especie cambia radicalmente su patrón de color a medida que envejece? Aquí presentamos dos ejemplos extraordinarios en especies del género Nembrotha basados en observaciones de laboratorio. Se recolectaron ejemplares de Nembrotha livingstonei Allan, 1933 y Nembrotha yonowae Goethel and Debelius, 1992 en Mozambique y se mantuvieron en cautiverio mientras fue posible alimentarlos. Los resultados mostraron que los patrones de color en ambas especies cambiaron con el tiempo y que este cambio estaba relacionado con la dieta. Además, el análisis de delimitación de especies y la comparación de las distancias por pares no corregidas de COI de ejemplares examinados de Mozambique y otros descargados de GenBank confirmaron que N. yonowae Goether y Debelius, 1992 es un sinónimo menor de N. cristata Bergh, 1877. Estudios similares con observaciones de laboratorio son necesarios en otras especies del género, ya que se describieron en función de una coloración diferente, pero la taxonomía integrada puede mostrar resultados diferentes

The genus Thordisa Bergh, 1877 (Mollusca: Gastropoda: Heterobranchia) in the Iberian Peninsula

El gènere Thordisa Bergh, 1877 (Mollusca, Gastropoda, Heterobranchia) a la península Ibèrica La família Discodorididae (Mollusca, Gastropoda, Nudibranchia) és una de les famílies de nudibranquis més nombroses quant a espècies i inclou gèneres coneguts en aigües europees com Discodoris Bergh, 1877, Geitodoris Bergh, 1891, Jorunna Bergh, 1876, Peltodoris Bergh, 1880, Platydoris Bergh, 1877 i Taringa Er. Marcus, 1955. També dins d’aquesta família es troba el gènere Thordisa Bergh, 1877, amb unes 25 espècies conegudes que viuen a tots els mars i oceans excepte els polars. Només s’han registrat 4 espècies de Thordisa en aigües europees: T. filix Pruvot-Fol, 1951, T. azmanii Cervera & García-Gómez, 1989, T. pallida Bergh, 1884 i T. aurea Pruvot-Fol, 1951, però les dues últimes són espècies mediterrànies que no s’han tornat a col·lectar des de la seva descripció. Aquí presentem nova informació anatòmica i biològica i dades de distribució d’exemplars recollits a la Península Ibèrica: Thordisa filix col·lectada al NE i exemplars de T. azmanii col·lectats al NO. També es discuteix la validesa de les altres dues espècies europees.The family Discodorididae (Mollusca, Gastropoda, Nudibranchia) is one of the most numerous nudibranch families in terms of species and includes well-known genera in European waters such as Discodoris Bergh, 1877, Geitodoris Bergh, 1891, Jorunna Bergh, 1876, Peltodoris Bergh, 1880, Platydoris Bergh, 1877 and Taringa Er. Marcus, 1955. This family also includes the genus Thordisa Bergh, 1877, with about 25 species, known to live in all seas and oceans except the polar ones. Only 4 species of Thordisa have been recorded in European waters: T. filix Pruvot-Fol, 1951, T. azmanii Cervera & García-Gómez, 1989, T. pallida Bergh, 1884 and T. aurea Pruvot-Fol, 1951, however the last two are Mediterranean species that have not been collected again since their original description. Here we present new anatomical and biological information and distribution data of specimens collected in the Iberian Peninsula: Thordisa filix collected in the NE and specimens of T. azmanii collected in the NW. The validity of the other two European species is also discussed

Barcoding a partir de posos de café - Explorando la biodiversidad de gasterópodos pterópodos a partir de posos de frascos de colección

Despite their cosmopolitan occurrence and massive plankton sampling during expeditions, the genetic diversity within Pteropoda Cuvier, 1804 is still largely unexplored. In this study we present a next-generation environmental barcoding approach to zooplankton bulk samples, which were collected during the circumglobal 2010 Malaspina expedition to evaluate pteropod diversity. We introduce a technique that avoids destructive procedures and leaves material intact for further morphological investigations. We extracted DNA out of the dregs (organic material such as mucus or body parts) of 27 sample containers for molecular barcoding (average 100-260 bp of COI). We were able to identify 7128 operational taxonomic units corresponding to the species composition contained in the examined samples. Among them were three species of thecosome pteropods, Creseis acicula, Creseis virgula and Cavolinia inflexa, which are discussed with respect to their taxonomy and their geographic distribution. Unidentified gymnosomes were also present in our samples from warmer regions in oceanic waters of the southern Indian Ocean. To facilitate identification of species, it is beneficial to create a better database of pteropod COI barcodes. Furthermore, gathering environmental barcoding data on a broad global scale will help to better understand species abundance and distribution of pteropods in the world’s oceans, and potentially those of other planktonic organisms.A pesar de su presencia cosmopolita y las actividades de muestreo masivo de plancton durante las expediciones, la diversidad genética dentro de los Pteropoda Cuvier, 1804 está todavía inexplorada en gran medida. En este estudio se presenta una aproximación desde el barcoding ambiental aplicada a muestras generales de zooplancton recogidas durante la expedición circumglobal “Malaspina 2010”, con el fin de evaluar la diversidad de pterópodos. Se introduce una técnica que evita procedimientos destructivos de tal modo que el material permanece intacto para futuras investigaciones morfológicas. Extrajimos ADN de los posos (material orgánico como moco o partes del cuerpo) de 27 recipientes de muestras para el barcoding (promedio de 100- 260 bp de COI). Se pudieron identificar 7128 “OTUs” correspondientes a la composición de las especies contenidas en las muestras examinadas. Entre ellas se encontraron tres especies de pterópodos tecosomados, Creseis acicula, Creseis virgula y Cavolinia inflexa, cuya taxonomía y distribución geográfica son discutidas. Gimnosomados no identificados procedentes de regiones más templadas de aguas oceánicas del sur del Océnao Indico también estaban presentes. Para facilitar la identificación de especies, es beneficioso crear una base de datos ampliada de códigos de barras COI de pterópodos. Además, la recopilación de datos de barcoding ambiental a una escala mundial amplia ayudará a comprender mejor la abundancia y distribución de especies de pterópodos en los océanos del mundo y de otros posibles organismos planctónicos

Can you find me? A new sponge-like nudibranch from the genus Jorunna Bergh, 1876 (Mollusca, Gastropoda, Discodorididae)

The nudibranch diversity of the western Indian Ocean is comparatively one of the least studied in the world. In this paper a sponge-like Discodoridae nudibranch Jorunna liviae sp. nov. is described. The description is based on integrative anatomy, including molecular analysis of two genes (the mitochondrial COI and the nuclear H3), dissections, electron microscopy (SEM) of buccal elements, micro tomography of the spicule’s arrangements and ecological observations. This study provides the first ever molecular data of Jorunna species from the western Indian Ocean, helping to fill the gap to further understand this apparent paraphyletic genus

A Spanish dancer? No! A troupe of dancers: a review of the family Hexabranchidae Bergh, 1891 (Gastropoda, Heterobranchia, Nudibranchia): A troupe of Spanish dancer

Color ontogeny and variations associated with discrete morphological differences may generate taxonomical challenges, which requires multiple data types and in-depth historical review. The nudibranch known as the Spanish dancer, Hexabranchus sanguineus, is a classic example with over 200 years of taxonomic confusion. Currently, H. sanguineus is accepted by most authors as a single species from the Indo-Pacific Ocean with Hexabranchus morsomus as a valid species from the Atlantic Ocean. Yet, despite these species being highly studied, their systematic status remains debatable. Over 30 synonyms have been proposed for H. sanguineus and even a distinct genus for H. morsomus. Here we provide, for the first time, a comprehensive review of all proposed names and an integrative taxonomic revision of the genus including morphological and molecular data. Our results reveal that H. sanguineus is a complex of five species: four previously described and an undescribed species, one of the largest nudibranchs in the world: Hexabranchus giganteus sp. nov. The genus Caribranchus is considered a junior synonym of Hexabranchus Ehrenberg, 1828 and the ontogeny of color pattern is discussed

Assessment of elemental composition in commercial fish of the Bay of Cádiz, Southern Iberian Peninsula

The assessment of trace metal content in our fish diet is important due to the adverse effect on human health. Despite the increasing interest about the fish quality, little information is available for Southern Spain, a region characterized by high seafood intake. Nine species from the Bay of Cádiz with high commercial value were selected. Similar values were measured in the nine studied species for most of the elements, except for the macroelements Ca and S, and the microelements Fe, Mn and As, which showed significant differences among species. Metal Pollution Index (MPI) did not differ among species, and it was similar to those obtained for other Atlantic and Mediterranean locations. The values measured for the nine species were below the health limits provided by World, European and Spanish legislations, indicating that, in general terms, consumption of these species is safe in the study area.9 página

Assessment of elemental composition in commercial fish of the Bay of Cádiz, Southern Iberian Peninsula

The assessment of trace metal content in our fish diet is important due to the adverse effect on human health. Despite the increasing interest about the fish quality, little information is available for Southern Spain, a region characterized by high seafood intake. Nine species from the Bay of Cádiz with high commercial value were selected. Similar values were measured in the nine studied species for most of the elements, except for the macroelements Ca and S, and the microelements Fe, Mn and As, which showed significant differences among species. Metal Pollution Index (MPI) did not differ among species, and it was similar to those obtained for other Atlantic and Mediterranean locations. The values measured for the nine species were below the health limits provided by World, European and Spanish legislations, indicating that, in general terms, consumption of these species is safe in the study area.We are very grateful to Dr. P. Burgos for chemical analysis conducted in IRNAS-CSIC (Instituto de Recursos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas, Sevilla). During the study, ID-A enjoyed a grant "Margarita Salas" financed by the European Union (Next Generation EU) and the Ministerio de Universidades of Spain

The origin and dispersal pathway of the spotted sea hare Aplysia dactylomela (Mollusca : Opisthobranchia) in the Mediterranean Sea

The spotted sea hare Aplysia dactylomela Rang, 1828 is a large and conspicuous opisthobranch sea slug that since 2002 has rapidly colonized the eastern Mediterranean, establishing populations in numerous localities. The source of the Mediterranean populations has been the subject of debate, with two main hypotheses considered (Atlantic and Red Sea origin). A recent study on the taxonomy of A. dactylomela has shown that the spotted sea hare is a complex of at least two genetically distinct species (A. dactylomela in the Atlantic and A. argus in the Indo-Pacific), facilitating the correct identification of Mediterranean specimens by molecular means. We used sequence data from the mitochondrial cytochrome oxidase I gene to identify the Mediterranean individuals for the first time and to infer their origin. Our results confirmed that all the specimens collected in the Mediterranean belong to A. dactylomela and therefore have an Atlantic origin. The limited sample size does not allow identification of the dispersal pathway of A. dactylomela into the Mediterranean, but the colonization sequence is consistent with a “natural” dispersal event. This hypothesis is evaluated in light of local surface circulation patterns. Possible causes for the recent and rapid invasion of the eastern Mediterranean by A. dactylomela are discussed.peer-reviewe

Population genetics of Bursatella leachii (De Blainville, 1817) and implications for the origin of the Mediterranean population

Abstract The sea hare Bursatella leachii (de Blainville 1817) (Mollusca: Gastropoda: Heterobranchia: Aplysiidae) is a pantropical sea slug that has colonized the Mediterranean Sea in modern times. Because the initial records in the non-native range started in the Eastern Mediterranean, and its pattern of spread was relatively consistent with those observed in well-known Lessepsian invaders, B. leachii is commonly considered to be a migrant from the Red Sea. In this study, we investigate for the first time the origin of the Mediterranean populations of B. leachii inferring their population structure and assessing relatedness levels of different regional populations. Sequence data from the cytochrome oxidase I were used to conduct population genetic analyses on this species, particularly by investigating the genetic structure of Atlantic, Mediterranean, and Indo-Pacific populations. Our results confirm that B. leachii is a truly pantropical species which displays geographic structure among major ocean basins. More importantly, sequenced Mediterranean and Atlantic animals share similar or identical haplotypes, which are distinct in at least 5 substitutions from haplotypes recovered from Indo-Pacific specimens. The results suggest that the Mediterranean population of B. leachii here examined probably have an Atlantic origin, and for the first time casts doubts on the assumed primary pathway of migration into the Mediterranean Sea