We revise the global diversity of the former genera Sergia and Sergestes which include 71 valid species. The revision is based on examination of more than 37,000 specimens from collections in the Natural History Museum of Denmark and the Museum of Natural History, Paris. We used 72 morphological characters (61 binary, 11 multistate) and Sicyonella antennata as an outgroup for cladistic analysis. There is no support for the genera Sergia and Sergestes as they have been defined until now. We define and diagnose eight genera of the former genus Sergia (Sergia and new genera Gardinerosergia, Phorcosergia, Prehensilosergia, Robustosergia, Scintillosergia, Challengerosergia, and Lucensosergia) and seven genera of the former genus Sergestes (Sergestes, Deosergestes, Eusergestes, Allosergestes, Parasergestes, Neosergestes, and a new genus Cornutosergestes). An identification key is presented for all genera of the family Sergestidae. The phylogeny of Sergestidae is mainly based on three categories of characters related to: (1) general decapod morphology, (2) male copulatory organs, and (3) photophores. Only simultaneous use of all three character types resulted in a resolved tree with minimal Bootstrap support 75 for each clade. Most genera are interzonal mesopelagic migrants, some are benthopelagic (Scintillosergia, Lucensosergia), bathypelagic (Sergia), or epipelagic (Cornutosergestes). Within each of meso- and benthopelagic genera there is one species with panoceanic distribution, while most species ranges are restricted to a single ocean. The genera demonstrate two different strategies expressed both in morphology and behavior: protective (Eusergestes, Sergestes, Cornutosergestes, Prehensilosergia, Scintillosergia, Lucensosergia, Challengerosergia, Gardinerosergia, Robustosergia, Phorcosergia, Sergia) and offensive (Neosergestes, Parasergestes, Allosergestes, Deosergestes).

The paper addresses the phylogeny and classification of the hydrothermal vent shrimp family Alvinocarididae. Two morphological cladistic analyses were carried out, which use all 31 recognized species of Alvinocarididae as terminal taxa. As outgroups, two species were included, both representing major caridean clades: Acanthephyra purpurea (Acanthephyridae) and Alpheus echiurophilus (Alpheidae). For additional support of the clades we utilised available data on mitochondrial Cytochrome c Oxidase I gene (CO1) and 16S ribosomal markers. Both morphological and molecular methods resulted in similar tree topologies and nearly identical clades. We consider these clades as evolutionary units and thus erect two new subfamilies: Rimicaridinae (Alvinocaridinides, Manuscaris, Opaepele, Shinkaicaris, Rimicaris), Alvinocaridinae (Alvinocaris), whilst recognising Mirocaridinae (with genera Mirocaris and Nautilocaris) at subfamily level. One genus, Keldyshicaris could not be assigned to any subfamily and is thus left as incertae sedis. The monophyly of Alvinocardinae was supported by morphological data, but not supported by molecular data (two analyses); the monophyly of all subfamilies was supported both by morphological and molecular data. Chorocaris is herein synonymized with Rimicaris, whilst Opaepele vavilovi is herein transferred to a new genus Keldyshicaris. Morphological trends within Alvinocarididae are discussed and short biogeographical remarks are given. We provide emended diagnoses for all subfamilies and genera along with keys to all recognized species.

In a changing ocean there is a critical need to understand global biogeochemical cycling, particularly regarding carbon. We have made strides in understanding upper ocean dynamics, but the deep ocean interior (> 1000 m) is still largely unknown, despite representing the overwhelming majority of Earth's biosphere. Here we present a method for estimating deep-pelagic zooplankton biomass on an ocean-basin scale. We have made several new discoveries about the Atlantic, which likely apply to the world ocean. First, multivariate analysis showed that depth and Chl were the basic factors affecting the wet biomass of the main plankton groups. Wet biomass of all major groups was significantly correlated with Chl. Second, zooplankton biomass in the upper bathypelagic domain is higher than expected. Third, the majority of this biomass comprises macroplanktonic shrimps, which have been historically underestimated. These findings, coupled with recent findings of increased global deep-pelagic fish biomass, suggest that the contribution of the deep-ocean pelagic fauna for biogeochemical cycles may be more important than previously thought.

Luciferidae is a family of peculiar and widely distributed shrimps with an unclear systematic position and uncertain internal phylogeny. We undertook

The first comprehensive phylogenetic study of the family Oplophoridae is based on four molecular markers and 87 morphological characters. We have examined and coded five major groups of morphological characters related to the rostrum (nine characters), the carapace (10), the abdomen and telson (34), the exopods (eight) and the armature of the posteriormost three pereopods (22). Abdomen/telson-linked characters are the most important in support of genus level and species-group level clades; abdomen/telson-linked, rostrum-linked characters and the armature of the last three pereopods explain the main bulk of speciation. Four robustly supported species groups within Systellaspis are designated: the S. debilis species group, the S. cristata species group, the S. braueri species group and the S. pellucida species group. We provide an amended key to all genera, species groups and species of Oplophoridae. We reveal three groups of morphological characters, which are likely coupled with the same locomotive function and thus evolved as a single unit: carapace, abdomen and exopods. We show that the armature of the posteriormost three pereopods evolved independently of other characters and suggest that this group is linked to such biological roles as mating and grooming.