Description of three new species of Bradyidius (Copepoda: Calanoida), the new aetideids from the deep Pacific Ocean, with notes on the genera Bradyidius and Aetideopsis.

Three new aetideid species, Bradyidius abyssalis sp. nov., Bradyidius parabyssalis sp. nov., and B. kurilokamchaticus sp. nov. are described from female specimens collected near the seafloor in the abyss of the Pacific and Atlantic Oceans. Specimens of Bradyidius parabyssalis sp. nov. were obtained in both the Atlantic and Pacific Oceans (Argentine Basin, area of the Meteor Seamount and the Kurile-Kamchatka Trench). Bradyidius abyssalis sp. nov. was found only in the Atlantic Ocean, (Brazil and Guinea Basins and area of the Meteor Seamount) and Bradyidius kurilokamchaticus sp. nov. was recorded from the Kurile-Kamchatka Trench of the Pacific Ocean. Three new herein described Bradyidius species constitute the first documented records of the genus from the abyss of the World Ocean. In addition, three Bradyidius species from the Weddell Sea, the Atlantic Ocean and the Kurile-Kamchatka Trench, are briefly described without biological names due to their bad condition. Bradyidius parabyssalis sp. nov. and B. abyssalis sp. nov. are distinguished from all known congeners by the presence of 3 setae at the basis of the mandible and morphological details of the prosome posterior corners and P1. They show close resemblance to each other but differ in body size, rostrum structure, P4 coxa armament and length of the setae of the antennule ancestral segment I and the mandible basis. Bradyidius kurilokamchaticus sp. nov. shares with B. curtus Markhaseva, 1993, B. pacificus (Brodsky, 1950) and B. arnoldi Fleminger, 1957 a rostrum with non-divergent or parallel points, but differs from these species in the size, the well developed lateral spine on exopod segment 1, in the number of setae at the antenna exopod segment 1 and some morphological details of the prosome posterior corners. Characters that define the genus Bradyidius Giesbrecht, 1897 from Aetideopsis Sars, 1903, i.e. the shape of lateral spines of P1exopod segments 1 and 2; the endopod of P2 segmentation and the setation of the antennule ancestral segments XII, XV and XVII are discussed.

Proteomic fingerprinting facilitates biodiversity assessments in understudied ecosystems: A case study on integrated taxonomy of deep sea copepods.

Accurate and reliable biodiversity estimates of marine zooplankton are a prerequisite to understand how changes in diversity can affect whole ecosystems. Species identification in the deep sea is significantly impeded by high numbers of new species and decreasing numbers of taxonomic experts, hampering any assessment of biodiversity. We used in parallel morphological, genetic, and proteomic characteristics of specimens of calanoid copepods from the abyssal South Atlantic to test if proteomic fingerprinting can accelerate estimating biodiversity. We cross-validated the respective molecular discrimination methods with morphological identifications to establish COI and proteomic reference libraries, as they are a pre-requisite to assign taxonomic information to the identified molecular species clusters. Due to the high number of new species only 37% of the individuals could be assigned to species or genus level morphologically. COI sequencing was successful for 70% of the specimens analysed, while proteomic fingerprinting was successful for all specimens examined. Predicted species richness based on morphological and molecular methods was 42 morphospecies, 56 molecular operational taxonomic units (MOTUs) and 79 proteomic operational taxonomic units (POTUs), respectively. Species diversity was predicted based on proteomic profiles using hierarchical cluster analysis followed by application of the variance ratio criterion for identification of species clusters. It was comparable to species diversity calculated based on COI sequence distances. Less than 7% of specimens were misidentified by proteomic profiles when compared with COI derived MOTUs, indicating that unsupervised machine learning using solely proteomic data could be used for quickly assessing species diversity.

Description of Bradyetes paramatthei sp. nov. (Copepoda: Calanoida), a new aetideid species from the deep Pacific Ocean with notes on the genus Bradyetes.

A new and rare aetideid species of the benthopelagic genus Bradyetes Farran, 1905 is described from female specimens collected near the seafloor from the abyss of the Pacific, Atlantic and Southern Oceans between 2000 and 2014. The new species, Bradyetes paramatthei sp. nov., is described from the Kurile-Kamchatka Trench (Pacific Ocean) and is additionally reported from the Angola and Guinea basins and from the Meteor Seamount of the Atlantic Ocean. Bradyetes paramatthei sp. nov. is related to the species B. matthei Johannessen, 1976, but differs in the shape of the prosome posterior corners, which are oval-rounded, and in the proximal segment of the antennal exopod, which is supplied with one seta. These two species are shown to constitute a separate species group within the genus Bradyetes. The other species group contains the remaining congeners including Bradyetes inermis Farran, 1905, for which morphological variability is discussed. Specimens of this species show diverse morphology and comprise 3 morphotypes distinguished by the P1, with a developed or absent lateral lobe , the P1 basal medial seta, which is either nude or supplied with setules, and by the different number of setae of the maxillule praecoxal arthrite.

Do molecular phylogenies unravel the relationships among the evolutionary young "Brafordian" families (Copepoda; Calanoida)?

Among the most derived calanoid copepod superfamily Clausocalanoidea about half of the genera belong to the so-called "Bradfordian" families that are defined by the presence of sensory setae at the maxilla and maxilliped. Many of these "Bradfordian" taxa are insufficiently well described, because their taxonomy is complicated and phylogenetic relationships are not completely resolved. We therefore aimed to unravel their phylogenetic relationships using molecular multi-gene analyses. We conducted molecular multi-gene analysis on 26 species from 15 genera representing all seven "Bradfordian" families using five gene fragments, the nuclear ribosomal 18S, 28S and internal transcribed spacer 2 DNA, and mitochondrial cytochrome c oxidase subunit I and cytochrome b. The monophyly of "Bradfordians" as one lineage in the superfamily Clausocalanoidea was supported by Maximum Likelihood and Bayesian Inference multi-gene analyses. Except for the support of species belonging to the same genus and specimens belonging to the same species, no phylogenetic relationships among genera and families were supported. The impossibility of resolving phylogenetic relationships among "Bradfordian" genera and families may be due to the young age or fast radiation of "Bradfordians" within the mostly derived calanoid superfamily Clausocalanoidea. Therefore, mutation rates might be not sufficient to track phylogenetic relationships. Evidence on phylogenetic relationships between genera and families remain unresolved after implementing integrated morphological and molecular taxonomic approaches.

New Sensiava species (Copepoda: Calanoida: Diaixidae) from the deep South Atlantic and first description of the female.

Females are described for the first time in the genus Sensiava Markhaseva & Schulz, 2006, that was known previously only from males. Four species of this genus are identified from samples collected in the vicinity of the abyssal sea bed. Two species, Sensiava secunda sp. nov. and S. peculiaris sp. nov. are named, and two species are not given names due to a poor condition of the examined specimens and their incomplete descriptions. Sensiava males have also been found in the samples. They share with their male congener Sensiava longiseta Markhaseva & Schulz, 2006 a geniculate right antennule, which is a plesiomorphy observed only in the benthopelagic Clausocalanoidea Giesbrecht, 1893. A differential diagnosis for the genus is given, based on both sexes. Sensiava was previously known only from the Antarctic waters between 63-64ºS, but its distributional range now can be extended significantly further to the north, up to the Equator in the South Atlantic.