Systematics of the Cumacea (Crustacea)

Cumaceans are small benthic crustaceans. They have a marine cosmopolitan distribution with diversity increasing with depth. There are approximately 1,400 described species of cumaceans. Despite the fact that they offer a good model for the study of morphological evolution and biogeography, the studies on the Order Cumacea are almost restricted to work at the alpha taxonomy level. This thesis contributes to the systematics of Cumacea. The phylogenetic relationships within the Cumacea were studied using newly obtained partial amino acid sequences from the mitochondria1 gene Cytochrome Oxidase I. Among other findings, phylogenetic analyses revealed that the families Bodotriidae, Leuconidae, and Nannastacidae, characterized by the presence of a pleotelson (telson fused to last abdominal segment), form a monophyletic and derived clade. The gene tree topology suggests that some characters traditionally used in cumacean diagnoses represent homoplasies. The cumacean family Bodotriidae is divided into three subfamilies and 34 genera with over 350 species, all of which were morphologically analyzed for 114 variable characters. Two main accomplishments were a result of this study. First, the phylogenetic relationships of the subfamilies and genera within the family were studied. The subfamily Mancocumatinae failed to resolve as a monophyletic group, the subfamily Vaunthompsoniinae are basal bodotriids, and the subfamily Bodotriinae is the most derived clade. A Tethyan origin for the bodotriid fauna is suggested, with radiation along the Atlantic Ocean during the Cretaceous. Phylogenetic and character evolution analyses support several changes to the classification of Bodotriidae. For example, the subfamily Mancocumatinae should be incorporated into the subfamily Vaunthornpsoniinae, the genus Coricuma should be incorporated into the Bodotriinae, and the species of the genera Heternma, Mossambicuma, Pseudocydaspis, should be incorporated into the genera Cumopsis, Eocuma and Cydaspis, respectively. Second, a comprehensive morphological work on the Family Bodotriidae was completed incorporating the suggested changes in the taxonomy . The generic review includes a dichotomous key and rediagnosis of each of the genera of the Family. A new species of Austrocuma from the eastern coast of lndii is described. Among other characters, the uniqueness of this species relies on the presence of onty four pleopods on the males

A multidisciplinary approach to identify pelagic shark fins by molecular, morphometric and digital correlation data

Accurate species identification is one of the most important issues to conserve and manage shark fisheries. A multidisciplinary approach involving molecular (using variation at ITS2 sequences), morphometrical and image processing species identification was performed to evaluate their discriminating power with three pelagic shark species common to the coasts of Chile (Prionace glauca Linnaeus 1785, Isurus oxyrinchus Rafinesque 1810, and Lamna nasus (Bonnaterre, 1788). Species-specific DNA markers and multivariate analyses based on twenty morphometrical measurements were used to identify fresh and dry fin sets for each shark species. Additionally, coloring patterns and fin shape were jointly used to distinguish dry fin sets of shark species by using digital invariant correlation (relation target and problem image independent of their changes in position, scale and rotation). Our results showed that morphometrical analysis was the least accurate approach, whereas DNA-based identification and image processing approaches were 100% successful on the identification of shark species. Thus ITS2 sequences and morphological diagnostic characteristics such as the ones related to color patterns, allow the correct identification of shark species. Therefore, the implementation of molecular and/or image tools can be applied to confidently identify the main pelagic shark species involved in Chilean landing and fin trade.Accurate species identification is one of the most important issues to conserve and manage shark fisheries. A multidisciplinary approach involving molecular (using variation at ITS2 sequences), morphometrical and image processing species identification was performed to evaluate their discriminating power with three pelagic shark species common to the coasts of Chile (Prionace glauca Linnaeus 1785, Isurus oxyrinchus Rafinesque 1810, and Lamna nasus (Bonnaterre, 1788). Species-specific DNA markers and multivariate analyses based on twenty morphometrical measurements were used to identify fresh and dry fin sets for each shark species. Additionally, coloring patterns and fin shape were jointly used to distinguish dry fin sets of shark species by using digital invariant correlation (relation target and problem image independent of their changes in position, scale and rotation). Our results showed that morphometrical analysis was the least accurate approach, whereas DNA-based identification and image processing approaches were 100% successful on the identification of shark species. Thus ITS2 sequences and morphological diagnostic characteristics such as the ones related to color patterns, allow the correct identification of shark species. Therefore, the implementation of molecular and/or image tools can be applied to confidently identify the main pelagic shark species involved in Chilean landing and fin trade

Hemilamprops chilensis sp. nov. (Crustacea: Cumacea: Lampropidae) from the coast of Chile, with a key to the Chilean Lampropidae and remarks on the status of H. ultimaespei Zimmer, 1921 and H. lotusae Băcescu, 1969

Gerken, Sarah, Haye, Pilar A. (2018): Hemilamprops chilensis sp. nov. (Crustacea: Cumacea: Lampropidae) from the coast of Chile, with a key to the Chilean Lampropidae and remarks on the status of H. ultimaespei Zimmer, 1921 and H. lotusae Băcescu, 1969. Zootaxa 4399 (3): 351-360, DOI: https://doi.org/10.11646/zootaxa.4399.3.

IDENTIFICACION MORFOLOGICA DE LAS ALETAS DE LOS PRINCIPALES TIBURONES PELAGICOS COMERCIALIZADOS EN CHILE: AZULEJO (PRIONACE GLAUCA LINNAEUS), MARRAJO (ISURUS OXYRHINCHUS RAFINESQUE), Y TINTORERA (LAMNA NASUS BONNATERRE) MORPHOLOGICAL IDENTIFICATION OF FINS OF THE MAIN TRADED PELAGIC SHARK SPECIES IN CHILE: BLUE SHARK (PRIONACE GLAUCA LINNAEUS), SHORTFIN MAKO (ISURUS OXYRHINCHUS RAFMESQUE), AND PORBEAGLE (LAMNA NASUS BONNATERRE)

La carencia de registros de desembarque especie-específicos ha producido dificultades en la evaluación de stock de tiburones en Chile. Debido a que los registros son insuficientes para realizar evaluaciones pesqueras, es imperativo contar con características fidedignas para la identificación de las especies o partes de éstas (como las aletas). El presente estudio describe caracteres morfológicos para la identificación de las aletas de las tres especies más importantes de tiburones pelágicos comercializados en Chile (P glauca, I. oxyrhinchusyL. nasus) y provee de claves dicotómicas para la identificación de estas especies usando ya sea la aleta pectoral, la primera dorsal o la caudal. Los resultados revelaron que existen caracteres diagnósticos para identificar las aletas de cada una de estas especies. Ya que las especies estudiadas son las que más se comercializan, las descripciones de las aletas y las claves taxonómicas por tipo de aleta desarrolladas en este estudio prometen ser de gran utilidad para los fiscalizadores, en particular aquellos que se enfrenten a los desembarques de sacos de aletas. Además, el poder conocer tanto la cantidad como la proporción de especies comercializadas, es importante para futuras evaluaciones pesqueras y el establecimiento de planes de manejo especie-específicos.<br>The lack of species-specific landing records has produced difficulties in shark stock assessments in Chile. Given that the records are insufficient for fisheries assessments, it is imperative to have trustable morphological characteristics for the identification of species or parts of their bodies (such as fins). This study describes morphological characters useful for the identification of fins of the three main traded pelagic shark species (P. glauca, I. oxyrhinchus andL. nasus). Results showed that there are diagnostic morphological characters to identify the fins of these three species. Given that the studied species are the most traded ones, the descriptions of the fins and the taxonomic keys per fin type developed in this study should be of high use to monitor landings of shark, especially fins in sacs. The knowledge of the proportion of traded species and the quantity of each is important for future fisheries assessments and the establishment of management plans

Time or Space? Relative Importance of Geographic Distribution and Interannual Variation in Three Lineages of the Ascidian Pyura chilensis in the Southeast Pacific Coast

Este artículo contiene 12 páginas, 3 figuras, 6 tablas.Spatial and temporal variation of environmental parameters can affect dispersal, recruitment and population persistence of marine benthic species. Studies including inter-annual comparisons of genetic structure often indicate high/moderate temporal heterogeneity in marine invertebrates, which may be a prevailing pattern. This suggests that temporal studies are necessary to understand the dynamics of marine metapopulations. In this study, we analyzed the spatio-temporal genetic structure of the ascidian Pyura chilensis, a low dispersal sessile marine species endemic from the Southeast Pacific coast and highly demanded for human consumption. We sequenced a fragment of the mitochondrial gene Cytochrome Oxidase I (COI) from 1,005 individuals of six locations (30–40 individuals per site and year) spanning a wide latitudinal range (24◦–42◦S) and sampled over 5 years (2012, 2014, 2015, 2016, and 2017). The genetic structure of COI indicates the presence of three monophyletic lineages (haplogroups 1–3) previously described for the species, being one of them highly divergent and geographically restricted (˜39◦S, Los Molinos). Considering the whole dataset, a picture of strong spatial differentiation but temporal stability emerged in Pyura chilensis. However, detailed studies of the two main lineages revealed important differences in the extent of spatio-temporal variation. Analyses using haplotype frequencies sorted by site and year showed that, for haplogroup 1, genetic variation was explained mainly by differences between sites, while for haplogroup 2 differences between years were prevailing. Haplogroup 3 was restricted to the most southern sites, and also showed inter-annual variability in its frequency. These results point to disparate patterns of genetic differentiation, which may reflect different adaptive scope or variation in reproductive and dispersal features and could be a response to extreme events such as El Niño (2015–2016). This work calls for caution when obtaining general trends in species clearly differentiated in lineages, and prompts instead for separate analyses of sub-specific genetic lineages whenever possible.This study was funded by the Chilean National Fund for Scientific and Technological Development through Grants FONDECYT 1140862, FONDECYT 3190482, Millennium Science Initiative Program—ICN2019_015, and partly funded by project PopCOmics CTM2017-88080 (MCIU/AEI/FEDER) of the Spanish Government.Peer reviewe

Signatures of local adaptation in the spatial genetic structure of the ascidian Pyura chilensis along the southeast Pacifc coast

The highly heterogeneous Humboldt Current System (HCS) and the 30 degrees S transition zone on the southeast Pacific coast, represent an ideal scenario to test the influence of the environment on the spatial genomic structure in marine near-shore benthic organisms. In this study, we used seascape genomic tools to evaluate the genetic structure of the commercially important ascidian Pyura chilensis, a species that exhibits a low larval transport potential but high anthropogenic dispersal. A recent study in this species recorded significant genetic differentiation across a transition zone around 30 degrees S in putatively adaptive SNPs, but not in neutral ones, suggesting an important role of environmental heterogeneity in driving genetic structure. Here, we aim to understand genomic-oceanographic associations in P. chilensis along the Southeastern Pacific coast using two combined seascape genomic approaches. Using 149 individuals from five locations along the HCS, a total of 2,902 SNPs were obtained by Genotyping-By-Sequencing, of which 29-585 were putatively adaptive loci, depending on the method used for detection. In adaptive loci, spatial genetic structure was better correlated with environmental differences along the study area (mainly to Sea Surface Temperature, upwelling-associated variables and productivity) than to the geographic distance between sites. Additionally, results consistently showed the presence of two groups, located north and south of 30 degrees S, which suggest that local adaptation processes seem to allow the maintenance of genomic differentiation and the spatial genomic structure of the species across the 30 degrees S biogeographic transition zone of the Humboldt Current System, overriding the homogenizing effects of gene flow.Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT FONDECYT 1140862 FONDECYT 319048

On the advantage of sharing a holdfast: effects of density and occurrence of kin aggregation in the kelp Lessonia berteroana

International audienceWe investigated the density-dependent and genetic relatedness that regulate the occurrence of inter-individual (genet) fusion forming plurigenotypic organisms in the brown alga Lessonia berteroana . Recruitment generally occurs at high densities in the inter-tidal, allowing contact of eighbouring holdfasts as they grow and expand on the substrate. Algal density, by contrast, is regulated by the effects of herbivory and wave impact, which often lead to low holdfast density. Herein, we investigated whether the occurrence of plurigenotypic organisms and their genotypic composition (number of genotypes per plurigenotypic organism) are density dependent and affected by kin selection in the inter-tidal kelp L. berteroana . Four microsatellite loci were used to analyse DNA from 260 samples obtained from shared and non-shared holdfasts, at two sites with highand two site with low holdfast density. Analyses showed that fusions forming plurigenotypic organisms are extremely common. Interestingly, the frequency of fusions was higher in low-density sites, in which 100% of the plants had at least two genotypes and the average was 3.5. In high-density sites, 62% of plants were plurigenotypic, with an average of 2.8 genotypes per plant. Additionally, we found that genotypes that shared a holdfast had a significantly higher genetic relatedness than the average in the population, compatible with a kin structure. Density dependence and kin structure suggest that the occurrence of plurigeno-typic organisms is linked to environmental quality, and that kin or multilevel selection may be favouring the fusion of genetically related genets