Marine Biodiversity最新文献

Here, we characterise the standard “Folmer region” of the mitochondrial cytochrome c oxidase subunit 1 (CO1) marker and a fragment of nuclear 28S marker in four species of the Jaera albifrons complex. Jaera albifrons (Leach, 1814), Jaera ischiosetosa Forsman, 1949, Jaera praehirsuta Forsman, 1949, and Jaera forsmani Bocquet, 1950 were collected from localities on the Norwegian coast and identified with morphological characters. We compared DNA sequences with sequences available in GenBank and BOLDsystems and calculated haplotype networks and interspecific versus intraspecific genetic distances. These analyses revealed low interspecific genetic distance (CO1 0.00–1.57%, 28S 0.00–0.39%) and extensive haplotype sharing between J. albifrons group species and specimens from both sides of the North Atlantic for both CO1 and 28S. Genetic distances between J. albifrons group species and other Jaera species, however, exceeded 29% for both CO1 and 28S, with no haplotype sharing. These assessments, together with taxonomically unconstrained analyses with software ABGD and ASAP, show that these markers are unable to distinguish between the J. albifrons group of morphospecies. The sequences do, however, clearly identify J. albifrons species complex from other Jaera species. Thus, a likely hypothesis is that taxa in this complex represent a single species. Our results corroborate previous finds where discordance between mitochondrial gene clusters, AFLP, and other data highlights the potential conflict between different “species criteria” and the well-established distinction between gene trees and species trees. In operational terms, common protocols for metabarcoding will potentially underestimate sympatric species diversity with cases like the J. albifrons complex, if the members of this complex indeed represent different species.

The harbour porpoise (Phocoena phocoena) is considered part of the ‘Outstanding Universal Value’ characterising the Wadden Sea World Heritage Site (WS WHS). The Trilateral Wadden Sea Plan aims to preserve the conservation status of the Trilateral Wadden Sea Cooperation Area, encompassing the WS WHS. The plan has specified two conservation targets for the harbour porpoise: (1) viable stocks and a natural reproduction capacity and (2) conservation of habitat quality for its conservation. To assess the current occurrence of the harbour porpoise in the Wadden Sea area, we collated and analysed data from regional and national research projects using telemetry, aerial surveys, strandings and passive acoustic monitoring, obtained over the years 1990–2020. The results illustrate that porpoises occur in both offshore and intertidal waters, showing seasonal movements and changes in local occurrence over time. Some porpoises displayed limited home ranges throughout the year, suggesting a possible residency for some of the animals using the Wadden Sea area. We also showed that methods, frequency and spatial coverage of monitoring activities vary among the countries Denmark, Germany and the Netherlands. We discuss the suitability of the different methods both regarding the challenges of monitoring in the complex Wadden Sea habitat as well as their ability to target the conservation aims of the WHS. We give several recommendations to assess the status of the species to meet the identified conservation aims.

The selection of specific bioinformatic pipelines to analyse Next Generation Sequencing (NGS) data is instrumental for generating accurate biological inferences; users should understand the limitations of the pipelines and incorporate existing biodiversity information to evaluate results. Pipelines that maximize the coverage and precision of taxonomic inventories and are in line with local biodiversity characteristics should be preferred. Environmental DNA (eDNA) metabarcoding based on NGS technology is projected to be widely employed for biomonitoring applications and to supplement established ways of monitoring marine biodiversity. In Indonesia, research has concentrated on assessing taxonomic composition in various geographical and environmental situations and on identifying taxa that are susceptible to environmental changes. This study aims to compare four NGS data analysis pipelines (Anacapa, QIIME2 with DADA2, QIIME2 with Deblur and Galaxy) using a 28-sample subset of published eDNA seawater samples collected from seawater across Indonesia. The outputs of the bioinformatics analyses between the pipelines differed. Anacapa, QIIME2 with DADA2, and Galaxy pipelines provide more comprehensive taxonomic coverage relevant to existing biodiversity records from the regions compared to QIIME2 with Deblur. Anacapa in particular could successfully detect taxa that have not been detected with other pipelines tested. These findings should be taken into account when doing eDNA metabarcoding analyses, especially when assessing marine biodiversity in terms of species diversity and abundance.

The genus Antholoba Hertwig, 1882 (Actiniaria, Enthemonae) is characterized by the presence of short and numerous tentacles, a folded oral disc in lobes or cup-shaped with an expanded distal part, transversely wrinkled body wall surface, a very long mesogloeal sphincter, parietobasilar muscles poorly developed, and the absence of acontia. Currently, the genus Antholoba is classified within the family Actinostolidae Carlgren, 1893 (superfamily Actinostoloidea Carlgren, 1932) and comprises two valid species: A. achates (Drayton in Dana, 1846) which have been recorded in Antarctica, the southwestern Atlantic, and the southeastern-western Pacific; and A. perdix (Drayton in Dana, 1846) which is distributed in the northwestern Atlantic, including the Gulf of Mexico. In recent collections along Ubatuba Bay in northern São Paulo, Brazil, we found specimens of a third, unknown species, which exhibits morphological and genetic differences from the only other species recorded from that place, A. achates (Drayton in Dana, 1846). Additionally, we examined five specimens of A. achates collected in Penha, Santa Catarina State, for morphological comparison. Our phylogenetic analyses, using molecular data, affirm the difference between the two species. Furthermore, the resultant phylogenetic trees recover the species of the genus Antholoba as a sister group to the acuticulate clade, within the superfamily Metridioidea, instead of within Actinostoloidea. We describe the material from Ubatuba as a new species, A. fabiani sp. nov., providing information and photographs of its external and internal anatomy, as well as cnidom, along with sequences of mitochondrial (12S, 16S, and COIII) and nuclear (18S and 28S) markers. Additionally, we propose placing the genus Antholoba within Metridioidea, and introduce the new family Antholobidae fam. nov.

Abstract

The slipper limpet Crepipatella dilatata, native to Chile and Argentina, was introduced in north-western Spain in 2005 and since then has spread to the Galician and Cantabrian coasts. In this work, we provide the first molecularly validated record of an established population of C. dilatata in central Portugal (Aveiro), and of reproductive individuals (i.e. brooding females) of C. dilatata in the Mediterranean Sea, from three Italian mussel farms (in eastern Sardinia and northern Adriatic). DNA barcoding and phylogenetic analyses based on mitochondrial markers indicate that limpets from Italian farms belong to the C. dilatata ‘clade1’, whereas limpets collected in Aveiro cluster within the C. dilatata ‘clade2’. All these limpets share the same COI haplotypes with introduced populations from Galicia. The arrival of C. dilatata to Europe is undoubtedly due to transoceanic live mussel trade from southern Chile to Galicia. Mussel trade and farming are also the most likely drivers for the post-border dispersal of C. dilatata from Spain to Portugal and to Italy. Several countries have a potential role as a hub for the primary and secondary dispersal of slipper limpets towards and within Europe. This calls the attention for future research focused on assessing the current occurrence and ecological impact of established populations of slipper limpets within and nearby mussel farms along the eastern Atlantic and Mediterranean coasts.

The southern Gulf of Mexico presents a wide diversity of habitats and fish, which makes it important for its natural resources, and the expansion of the fishing, port, and oil industry. In the present study, physicochemical parameters, and the biomass, density, and functional arrangement of the fish community were contrasted over 32 stations and three years (2011–2013) to establish a baseline and assess constraints in the ecosystem diversity and resilience. Were recorded 102 species classified into 14 functional groups (FGs) and four functional independent species (FIS). The species with the greatest effect on the ecosystem due to their biomass and density are three benthic carnivorous species Ariopsis felis, Eucinostomus gula, and Syacium gunteri, and the most representative due to their great length are two benthopelagic carnivorous species, Trichiurus lepturus and Fistularia petimba (~ 234–200 cm total length). There was no spatial or temporal variation related to the physicochemical variables, biomass, density, and functional arrangement and due to the functional diversity and redundancy found, we can conclude that the southern Gulf of Mexico is a stable ecosystem and thus might be resilient. We recommend monitoring seven FGs and four FIS to ensure the balance between the redundant and unique functions in the ecosystem is maintained: ZoNS and ZoNM representing the most redundant functions; ZoS, ZoM, ZS, and NM since they present highly specific diets; PZoM is the only FG including plant matter in their diet; PZoS which include plant matter, and ZoZM, ZM, and NS because of their unique function in the system.

The macrofauna in soft sediments of the deep seafloor is generally diverse and represents a comparatively well-studied faunal group of deep-sea ecosystems. In the abyss of the Clarion Clipperton Fracture Zone (CCFZ) in the NE Pacific, macrofauna are major contributors to benthic biodiversity. Their distribution, composition, and diversity have been frequently investigated to assess the potential impacts of future mining activities on the resident fauna. In this study, patterns of densities and community structure of CCFZ macrobenthic infauna and their relationships with a range of environmental and climatic variables were examined, with a special focus on communities from the eastern German contract area (referred to as BGR CA). However, comparisons were also made with other contractor areas (e.g., IFREMER, IOM, GSR) and one Area of Particular Environmental Interest (APEI3). Material for this study was obtained by means of a box corer during six expeditions to the CCFZ between 2013 and 2018 resulting in 148 samples. Our study uncovered notable spatial and temporal variations in both faunal densities and community composition. While areas within the BGR CA exhibited a similar community composition, slight differences were observed between the various CAs and APEI3. Surprisingly, we found an unexpected negative correlation between food availability and both macrofaunal density and community structure that may be attributed to differences in sampling methodologies and pronounced temporal variation. Furthermore, we explored the impact of climatic fluctuations associated with the El Niño/Southern Oscillation (ENSO) on macrofaunal densities, observing an increase during warm (El Niño) events. Our findings underscore the challenges of accurately assessing spatial and temporal variations in the absence of standardised sampling protocols. Hence, we emphasize the importance of adopting standardised protocols to enhance data comparability, thereby fostering a deeper understanding of the underlying factors influencing spatial and temporal changes in macrofauna community structure within the CCFZ.

Sharks rubbing against ocean floor or rocks are common events in marine environments, while instances of interspecific shark chafing behavior have been observed much less frequently. This behavior has garnered scientific interest in recent years and usually involves a smaller shark rubbing against a larger species, utilizing dermal denticles to rid itself of parasites or dead skin cells. Despite the costs and benefits of this behavior being not yet fully understood, we report new evidence of grey reef sharks (Carcharhinus amblyrhynchos Bleeker, 1856) engaging in chafing behavior against whale shark (Rhincodon typus Smith, 1828) in the Maldives. This behavior suggests that grey reef sharks may engage in chasing behavior for cleaning purposes or take advantage of larger sharks as an anti-predation tactic. These records contribute to shed light on previously unexplored aspects of elasmobranch interspecies interactions and highlight the need for further research into this topic. The prevalence of such behavior across different regions suggests its potential significance in the ecological dynamics of shark population.