Lanternfish Diaphus spp. specimens of a DNA barcoding survey of the mesopelagic micronekton communities of the New Caledonia and Wallis-and-Futuna EEZ

This document includes 25 plates of annotated photographs of lanternfish Diaphus spp. specimens collected during cruises ESSCHA, NECTAlis, PUFFAlis and WALLAlis of R.V. Alis in the Coral Sea, the Fiji Basin, and the Pacific Ocean around Wallis-and-Futuna Islands. Specimens were grouped by operational taxonomic unit, defined (OTU) as the cluster to which they belonged in a phylogenetic tree of sequences of a portion of the CO1 gene. Species assignment was initially based on the morphological identification of reference specimens, i.e., particularly-well preserved specimens that exhibit the diagnostic characters mentioned in diagnoses and iden-tification keys from the published literature. In several instances, the same species was represented by distinct OTUs.Ce document comprend 25 planches de photographies annotées de spécimens de poissons-lanternes du genre Diaphus récoltés lors des campagnes ESSCHA, NECTAlis, PUFFAlis et WALLAlis du R.V. Alis dans la mer de Corail, le bassin des Fidji et l'océan Pacifique autour des îles Wallis-et-Futuna. Les spécimens ont été regroupés par unité taxonomique opérationnelle (OTU), définie comme le groupe auquel ils appartenaient dans un arbre phylogénétique des séquences d'un fragment du gène de la CO1. L'attribution à l’espèce a initialement été faite à partir de l'identification morphologique de spécimens de référence, c'est-à-dire de spécimens particulièrement bien conservés qui présentent les caractères diagnostiques mentionnés dans la littérature. Dans plusieurs cas, la même espèce était représentée par des OTUs distinctes

Lanternfish Diaphus spp. specimens of a DNA barcoding survey of the mesopelagic micronekton communities of the New Caledonia and Wallis-and-Futuna EEZ

This document includes 25 plates of annotated photographs of lanternfish Diaphus spp. specimens collected during cruises ESSCHA, NECTAlis, PUFFAlis and WALLAlis of R.V. Alis in the Coral Sea, the Fiji Basin, and the Pacific Ocean around Wallis-and-Futuna Islands. Specimens were grouped by operational taxonomic unit, defined as the cluster to which they belonged in a phylogenetic tree of sequences of a portion of the CO1 gene. Species assignment was initially based on the morphological identification of reference specimens, i.e., particularly-well preserved specimens that exhibit the diagnostic characters mentioned in diagnoses and identification keys from the published literature.Ce document comprend 25 planches de photographies annotées de spécimens de poissons-lanternes du genre Diaphus récoltés lors des campagnes ESSCHA, NECTAlis, PUFFAlis et WALLAlis du R.V. Alis dans la mer de Corail, le bassin des Fidji et l'océan Pacifique autour des îles Wallis-et-Futuna. Les spécimens ont été regroupés par unité taxonomique opérationnelle, définie comme le groupe auquel ils appartenaient dans un arbre phylogénétique des séquences d'un fragment du gène de la CO1. L'attribution à l’espèce a initialement été faite à partir de l'identification morphologique de spécimens de référence, c'est-à-dire de spécimens particulièrement bien conservés qui présentent les caractères diagnostiques mentionnés dans la littérature

Lanternfish Diaphus spp. specimens of a DNA barcoding survey of the mesopelagic micronekton communities of the New Caledonia and Wallis-and-Futuna EEZ

This document includes 25 plates of annotated photographs of lanternfish Diaphus spp. specimens collected during cruises ESSCHA, NECTAlis, PUFFAlis and WALLAlis of R.V. Alis in the Coral Sea, the Fiji Basin, and the Pacific Ocean around Wallis-and-Futuna Islands. Specimens were grouped by operational taxonomic unit, defined (OTU) as the cluster to which they belonged in a phylogenetic tree of sequences of a portion of the CO1 gene. Species assignment was initially based on the morphological identification of reference specimens, i.e., particularly-well preserved specimens that exhibit the diagnostic characters mentioned in diagnoses and iden-tification keys from the published literature. In several instances, the same species was represented by distinct OTUs.Ce document comprend 25 planches de photographies annotées de spécimens de poissons-lanternes du genre Diaphus récoltés lors des campagnes ESSCHA, NECTAlis, PUFFAlis et WALLAlis du R.V. Alis dans la mer de Corail, le bassin des Fidji et l'océan Pacifique autour des îles Wallis-et-Futuna. Les spécimens ont été regroupés par unité taxonomique opérationnelle (OTU), définie comme le groupe auquel ils appartenaient dans un arbre phylogénétique des séquences d'un fragment du gène de la CO1. L'attribution à l’espèce a initialement été faite à partir de l'identification morphologique de spécimens de référence, c'est-à-dire de spécimens particulièrement bien conservés qui présentent les caractères diagnostiques mentionnés dans la littérature. Dans plusieurs cas, la même espèce était représentée par des OTUs distinctes

Detection of shrimp pathogen Vibrio nigripulchritudo in sediments of a New-Caledonian grow-out pond during a drying period

Experimental infections together with epidemiological studies have shown that pathogenic and non‐pathogenic isolates of V. nigripulchritudo co‐existed in shrimp farm environment (2, 3). Moreover, obtained results also demonstrated that the “summer syndrome”was caused by a single, possibly emerging, cluster of virulent strains. Consequently, it was hypothesized that pathogenic strains of V. nigripulchritudo may persist from one year to the next in the shrimp farm environment and re‐develop inside the grow‐out system at the following rearing cycle (3). This study was therefore aimed at determining whether V. nigripulchritudo isolates may survive, or not, in a shrimp pond bottom soil during a 18‐week drying period. To this end, V.nigripulchritudo mapping was performed with recently developed molecular tools and classical culture‐dependent techniques

Biogeography of Micronekton Assemblages in the Natural Park of the Coral Sea

WOS:000558706200001International audienceMesopelagic resources are central to the ecosystem but remain poorly studied mainly due to the lack of observations. This paper investigates the assemblages of micronekton organisms and their habitat in the Natural Park of the Coral Sea around New Caledonia (southwest Pacific) using data from 141 pelagic trawls. A total of 67,130 micronekton individuals (fish, crustaceans, and mollusks) were collected with 252 species identified among 152 genus and 76 families. In the analyses, we focused on 22 species; each were present in more than 33 trawls (i.e., in more than 25% of the total number of trawls) and studied their spatial distribution and vertical dynamic behavior. Community structure was investigated through region of common profile (RCP), an innovative statistical multivariate method allowing the study of both species assemblages and environmental conditions' influence on species occurrence probability. Nine major assemblages were identified, mainly driven by time of the day and sampling depth. Environmental variables, such as mean oxygen concentration, mean temperature, and bathymetry, also influenced micronekton assemblages, inducing a north/south distribution pattern. Three major day-assemblages were identified, distributed over the whole EEZ but segregated by depth: one assemblage in waters shallower than 200 m and the other two in deeper waters, respectively, in the north and the south. The night-assemblages were mostly segregated by depth with two community changes at approximately 80 and 200 m and spatially with a north-south gradient. The predominant northern night assemblages were dominated by crustacean, whereas the southern assemblage mostly by cephalopods and fish species. Generally, the southwest part of the EEZ was the most diverse part. Statistical analyses allowed the prediction of the spatial distribution of each species, and its vertical migration behavior was determined. Based on results, three important areas were identified to be considered for special management measures as part of the Natural Park of the Coral Sea

Comparative analysis of day and night micronekton abundance estimates in west Pacific between acoustic and trawl surveys

International audienc

Variations in life history characteristics of the deep-water giant ruby snapper (Etelis sp.) between the Indian and Pacific Oceans and application of a data-poor assessment

The giant ruby snapper, Etelis sp., attains the largest size of any lutjanid in the Indo-Pacific and is one of the most valuable species harvested from deep-water fisheries along the continental and insular shelf margins throughout its broad geographic distribution. Despite this species supporting important commercial, artisanal and subsistence fisheries, quantitative assessments of the status of stocks have been limited by an absence of biological information, unreliable catch and effort statistics, and until recently, misidentification with a cryptic congener. This study aimed, firstly, to describe and compare the age, growth and reproductive characteristics of Etelis sp. between the eastern Indian and western central Pacific Oceans; and secondly, to provide an age-based assessment of the stock in north-western Australia, the only stock for which available data were sufficient to quantify stock status. Although the growth of Etelis sp. differed significantly between sexes and oceans, longevity was similar with a maximum age of 56 years recorded in the Pacific Ocean. Spawning of this species occurred over five months during the austral summer to mid-autumn (i.e. December to April) in the Indian Ocean, but was not well defined in the Pacific Ocean. The estimated ages at 50 % maturity for females and males in the Indian Ocean were similar (i.e. 4-5 years), whereas lengths at 50 % maturity differed (L-50(mat) = 527 and 456 mm fork length, FL, respectively), but were consistent with corresponding differences in growth between sexes. Estimates of the relative female spawning potential ratio for Etelis sp. in north-western Australia suggest the status of this stock remained relatively unchanged from 1997 to 2011, at around 60 % of the unfished level. This assessment provides an example of the relative sustainable exploitation levels for this stock, and potentially other Eteline snappers that exhibit similar life history characteristics, particularly in locations where monitoring and assessments may be data and/or resource limited

Marine mammal strandings recorded in New Caledonia, South West Pacific Ocean, 1877 to 2022

International audienceContextStrandings are an important source of information for estimating marine mammal biodiversity, particularly in data-sparse ocean basins such as Oceania.AimsHere, we report on knowledge acquired from 218 stranding events recorded in the waters of New Caledonia (1877–2022).MethodsWe investigated spatio-temporal distribution, stable isotope signatures, trace element concentrations, biometry measurements, genetic diversity, and diet, for the four most commonly stranded taxa (dugongs, 35% of events; sperm whales, 19%; Delphinidae, 18%; pygmy and dwarf sperm whales, 14%).Key resultsBeginning in 1991, reports of stranding events increased (183 events, 322 individuals, 20 species from seven families: Dugongidae, Physeteridae, Delphinidae, Kogiidae, Ziphiidae, Balaenopteridae, Otariidae), with hotspots identified on the west coast (Bourail, Ouano, Nouméa) and in Prony Bay. Causes of death were not determined in 84% of stranding events, but were identified in the majority of expert-led necropsies (24 of 29 individuals from 10 species). Yet, valuable information regarding the impact of anthropogenic activities was gathered for some species of concern, such as the endangered dugong (28% human-caused). Since 2016, training and outreach have been provided to rangers, veterinarians, and various public safety officers to support their engagement in the scientific monitoring of marine mammal strandings. A website (www.rescue.ird.nc) was developed to facilitate standardised data collection and storage, and to provide public access to stranding records.ConclusionAlthough the number of individuals reported here remains modest, this study provides new information on poorly documented species in New Caledonia.ImplicationsLong-term monitoring of strandings can help design effective conservation measures.ContexteLes échouages constituent une source d’informations importante pour estimer la biodiversité des mammifères marins, en particulier dans les bassins océaniques pour lesquels les données sont rares, comme l’OcéanieObjectifNous présentons ici les connaissances acquises à partir de 218 échouages enregistrés dans les eaux de Nouvelle-Calédonie (1877–2022).MéthodesNous avons étudié la distribution spatio-temporelle, les signatures isotopiques, les éléments traces, les mesures biométriques, la diversité génétique et le régime alimentaire des quatre taxons les plus fréquemment échoués (dugongs, 35% des échouages; cachalots, 19%; Delphinidae, 18% ; cachalots pygmées et nains, 14%).Principaux résultatsÀ partir de 1991, les signalements d’échouages ont augmenté (183 événements, 322 individus, 20 espèces de sept familles: Dugongidae, Physeteridae, Delphinidae, Kogiidae, Ziphiidae, Balaenopteridae, Otariidae), avec des points chauds identifiés sur la côte ouest de la Grande Terre (Bourail, Ouano, Nouméa) et dans la Baie de Prony. Les causes de décès n’ont pas été déterminées pour 84% des échouages, mais elles ont été identifiées dans la majorité des autopsies réalisées par des vétérinaires (24 des 29 individus de 10 espèces). Des informations précieuses concernant l’impact des activités anthropiques ont été recueillies pour certaines espèces préoccupantes, telles que le dugong, une espèce en voie de disparition (28% des échouages d’origine humaine). Depuis 2016, des formations et des activités de sensibilisation ont été dispensées aux gardes nature, aux vétérinaires et à divers agents publics pour soutenir leur engagement dans la surveillance scientifique des échouages de mammifères marins. Un site Web (www.rescue.ird.nc) a été développé pour faciliter la collecte et le stockage de données standardisées et pour fournir un accès public aux enregistrements d’échouages.ConclusionBien que le nombre d’individus signalés échoués ici reste modeste, cette étude apporte de nouvelles informations sur des espèces peu documentées en Nouvelle-Calédonie.ImplicationsLa surveillance à long terme des échouages peut aider à concevoir des mesures de conservation efficaces