Aim Marine species ranges are often large, contributing to relatively high community similarity over space, with decreased ranges expected among taxa that have lower dispersal and/or higher substrate requirements. We tested for a weakening of biogeographic structuring among dispersing abyssal taxa along the benthic to holoplanktonic habitat continuum by comparing geographic ranges and rates of community dissimilarity across th...

The abyssal benthic boundary layer (BBL) community relies on pelagic organic matter (OM) export, yet community dynamics under changing surface productivity remain poorly understood. Here, we describe temporal variability within the BBL zooplankton community, focusing on benthopelagic adults and meroplanktonic larvae at a site with seasonal OM flux. We test the hypothesis that BBL community composition, richness, and structure...

The deep seafloor serves as a reservoir of biodiversity in the global ocean, with >80% of invertebrates at abyssal depths still undescribed. These diverse and remote deep‐sea communities are critically under‐sampled and increasingly threatened by anthropogenic impacts, including future polymetallic nodule mining. Using a multigene environmental DNA (eDNA) metabarcoding approach, we characterized metazoan communities sampled fr...

In subtropical oceans phytoplankton carbon: phosphorus (C : P) ratios are high, and these ratios are predicted to increase further with rising ocean temperatures and stratification. Prey stoichiometry may pose a problem for copepod zooplankton nauplii, which have high phosphorus demands due to rapid growth. We hypothesised that nauplii meet this demand by consuming bacteria. Naupliar bacterial and phytoplankton carbon and phos...

Several studies have found that the respiratory demand for carbon by the mesopelagic community exceeds carbon supply through the particulate sinking flux by up to two to three orders of magnitude, suggesting that mesopelagic communities rely on additional overlooked carbon sources. Suspended particles (defined as 0.7–53 μ m) have been suggested as one of these sources but few studies have evaluated their contribution to the me...

Although metazoan animals in the mesopelagic zone play critical roles in deep pelagic food webs and in the attenuation of carbon in midwaters, the diversity of these assemblages is not fully known. A metabarcoding survey of mesozooplankton diversity across the epipelagic, mesopelagic and upper bathypelagic zones (0–1500 m) in the North Pacific Subtropical Gyre revealed far higher estimates of species richness than expected giv...

Large population sizes and high dispersal potential should lead to temporal genetic stability in marine species; however, the magnitude of allele frequency shifts through time have varied greatly in prior studies. We investigated temporal variation in the genetic composition of populations of two planktonic copepod species at an open ocean time series site in the North Pacific Subtropical Gyre (Station ALOHA, 22.45°N, 158°W)....

Zooplanktonic taxa have a greater number of distinct populations and species than might be predicted based on their large population sizes and open‐ocean habitat, which lacks obvious physical barriers to dispersal and gene flow. To gain insight into the evolutionary mechanisms driving genetic diversification in zooplankton, we developed eight microsatellite markers to examine the population structure of an abundant, globally d...

We investigated population genetic structure within and between ocean basins in the common mesopelagic copepod, Haloptilus longicornis, using the mitochondrial marker cytochrome oxidase subunit II (mtCOII, 43 locations, n = 1059). We found highly significant genetic divergence among ocean basins (global F ST = 0.20; p F CT = 0.21, Pacific: F CT = 0.15, AMOVA, p F CT measures genetic divergence among groups). In the Atlantic, a...

Species discovery through large‐scale sampling of mitochondrial diversity, as advocated under DNA barcoding, has been widely criticized. Two of the primary weaknesses of this approach, the use of a single gene marker for species delineation and the possible co‐amplification of nuclear pseudogenes, can be circumvented through incorporation of multiple data sources. Here I show that for taxonomic groups with poorly characterized...

Using three‐dimensional (3D) video observations in laboratory experiments, I describe interspecific and intergeneric mating behaviors and motility patterns of the common planktonic marine copepods Centropages typicus , Centropages hamatus , and Temora longicornis . These observations are then used to estimate heterospecific and conspecific male mate‐search volume rates and mate encounter rates in North Sea Centropages populati...

We examined the reproductive biology and genetic structure of the polychaete Bathykurila guaymasensis (Annelida: Polynoidae), a species recorded from both whale‐falls and hydrothermal vents. The habitat of B. guaymasensis is quite different from other vent polynoids, being apparently a specialist feeder on Beggiatoa mat, rather than living commensally with mussels or on the sides of hot vent chimneys. Specimens were collected...