Hundreds of genetic barcodes of the species-rich hydroid superfamily Plumularioidea (Cnidaria, Medusozoa) provide a guide toward more reliable taxonomy

Marine hydroids are important benthic components of shallow and deep waters worldwide, but their taxonomy is controversial because diagnostic morphological characters to categorize taxa are limited. Their genetic relationships are also little investigated. We tested taxonomic hypotheses within the highly speciose superfamily Plumularioidea by integrating a classical morphological approach with DNA barcoding of the 16S and COI mitochondrial markers for 659 and 196 specimens of Plumularioidea, respectively. Adding Genbank sequences, we inferred systematic relationships among 1,114 plumularioids, corresponding to 123 nominal species and 17 novel morphospecies in five families of Plumularioidea. We found considerable inconsistencies in the systematics of nominal families, genera and species. The families Kirchenpaueriidae and Plumulariidae were polyphyletic and the Halopterididae paraphyletic. Most genera of Plumularioidea are not monophyletic. Species diversity is considerably underestimated. Within our study, at least 10% of the morphologically-distinctive morphospecies are undescribed, and about 40% of the overall species richness is represented by cryptic species. Convergent evolution and morphological plasticity therefore blur systematic relationships. Additionally, cryptic taxa occur frequently in sympatry or parapatry, complicating correspondence with type material of described species. Sometimes conspecificity of different morphotypes was found. The taxonomy of hydroids requires continued comprehensive revision.This work relied on several hydrozoan samples collected from various sites, with the aid of many people. Supplementary Table S1 refers many of the people involved in the collection and/or preservation of the samples. C.J.M. acknowledges his great buddy-divers Jaime N.-Ruiz (CIMAR, Univ. Costa Rica), Axel Calderon, Nathaniel Chu, Eleni Petrou (STRI, Smiths. Inst.), Hanae Spathias, Karen Koltes (at the Belize station, Smith. Inst.), Freya Sommer (Hopkins Marine Station), Remilson Ferreira ('Costa Norte', Sao Tome), Frederico Cardigos (DOP, Univ. Azores) and others that assisted the dives. C.J.M. also acknowledges Rita Castillo (CIMAR, Univ. Costa Rica), Plinio Gondola, Ligia Calderon, Laura Geyer, Maria Castillo (STRI, Smiths. Inst.), Gregory Ruiz (SERC, Smiths. Inst.), Paul Greenhall, William Keel (MSC, Smith. Inst.), Manuel Enes, Valentina Matos (IMAR/DOP, Univ. Azores), Filipe Porteiro, Joao Goncalves (OKEANOS/IMAR, Univ. Azores), Marina Cunha, Ascensao Ravara (CESAM, Univ. Aveiro), Shirley Pomponi (Harbor Branch, Florida Atlantic Univ.), Estrela Matilde (Fundacao Principe Trust), Monica Albuquerque, Ines Tojeira (EMEPC), Diana Carvalho (Nat. Mus. Nat. Hist., Lisbon) and many others colleagues that facilitated the morphologic classifications and deposition of the samples. Peter Schuchert (Mus. d'Hist. Nat. Geneve) kindly provided some DNA extractes. Todd Kincaid and his team of GUE divers (Project Baseline - Azores) collected valuable samples from unusual depths. Joana Boavida (CIIMAR, Univ. Algarve) facilitated some samples of the 'DeepReefs' project. Jim Drewery (Marine Scotland Science Inst.) also provided few samples. Dale Calder (Royal Ontario Museum) provided some bibliography to C.J.M. and discussed/resolved some dubios taxonomic classifications. Colleagues at the L.A.B. (NMNH, Smith. Inst.) were very supportive. The APC fees for open access publication were supported by a program of the Regional Government of the Azores ("Apoio ao funcionamento e gestao dos centros de I&D regionais: 2018 - DRCT-medida 1

Moray eels are more common on coral reefs subject to higher human pressure in the greater Caribbean

Proximity and size of the nearest market (‘market gravity’) have been shown to have strong negative effects on coral reef fish communities that can be mitigated by the establishment of closed areas. However, moray eels are functionally unique predators that are generally not subject to targeted fishing and should therefore not directly be affected by these factors. We used baited remote underwater video systems to investigate associations between morays and anthropogenic, habitat, and ecological factors in the Caribbean region. Market gravity had a positive effect on morays, while the opposite pattern was observed in a predator group subject to exploitation (sharks). Environmental DNA analyses corroborated the positive effect of market gravity on morays. We hypothesize that the observed pattern could be the indirect result of the depletion of moray competitors and predators near humans. Environmental science; ecology; biological sciences; zoology; animals; etholog

Determination des temps d'arrivee en sismologie explosive par analyse energetique entre les passages a zero du signal

En sismologie explosive, la détermination des temps d'arrivée des ondes réfléchies permet de connaître la structure géologique de la croûte terrestre. Si on ne peut formuler d'hypothèses particulières sur le signal et sur les caractéristiques du bruit , il est possible d'utiliser l'énergie du signal sismique pour détecter l'arrivée de chaque onde. En effet le passage du front d'une onde est caractérisé par un accroisement de l'énergie suivi d'une diminution progressive correspondant à l'atténuation des mouvements du sol. L'utilisation d'une fenêtre glissante pour calculer cette énergie apporte un effet de lissage qui peut atténuer , sinon masquer de faibles arrivées. Afin de minimiser ce phénomène, le signal est découpé en "demi-excursions" correspondant aux mouvements du sol entre deux passages à zéro consécutifs de la trace sismique. Le calcul de l'énergie mise en jeu dans les différentes "demi-excursions" constituant le signal fournit une représentation fine des variations de l'énergie reçue par le sismomètre, La détermination des intervalles où cette énergie a tendance à croître permet de détecter des arrivées d'ondes superposées dans le domaine temporel. Les résultats obtenus en analysant des signaux recueillis au cours de campagnes d'exploration du sous-sol Marocain montrent l'intérêt de cette méthode simple et précise