Biology subjects

Tunnicliffe, V.

Publications and source records attributed to Tunnicliffe, V..

3 recordsLinked to original sources

bioRxiv2024

A tale of two shrimps - Speciation and demography of two sympatric shrimp species from hydrothermal vents

Hydrothermal vents can serve as natural laboratories to study speciation processes due to their fragmented distribution often with geographic barriers between habitats. Two sympatric species of Rimicaris shrimps occur at vents on the Izu-Bonin-Mariana volcanic arc: Rimicaris loihi also occurs near Hawaii and R. cambonae is present on the Tonga Arc. These two species biogeographically co-occur and are genetically similar, raising questions about their speciation mechanism, how they maintain distinct species, and whether interbreeding occurs. Here, we use barcoding and shotgun sequencing to test their genetic isolation and investigate their speciation process. We also evaluate population demography over 10 years to assess population densities and sex ratios at vents. Our results support R. cambonae and R. loihi as two distinct species despite sympatry throughout part of their range. We also observed regional-scale genetic structure among R. loihi populations from the Izu-Bonin-Mariana volcanic arc despite their broad geographic distribution. Finally, we found concomitant variations of shrimp densities and genetic diversity following fluctuations in geological and venting activities over a decade. A combination of geological instability, ocean currents dynamics and sea-level changes might drive temporary isolation among these local populations. We suggest similar factors, with longer isolation periods, may also have promoted speciation between the two Rimicaris species whereas distinct life-history traits could strengthen and maintain reproductive barriers. Overall, our results indicate different connectivity patterns on a volcanic arc that contrast with those observed previously at vents from mid-ocean ridges or back-arc basins systems.

evolutionary biology↗

bioRxiv2023

Hydrothermal vent fauna of the Galapagos Rift: Updated species list with new records

The sighting of giant bivalves and tubeworms at the Rose Garden vent field on the Galapagos Rift in 1977 marked the discovery of hydrothermal vents, a turning point for modern biology. The following decade saw a flurry of taxonomic descriptions of vent endemic species from the first vents. With the finding of high-temperature black smokers on the East Pacific Rise, exploration shifted away from Galapagos. A faunal list of Galapagos vents with 65 species was published in 1991, then updated to 74 species in 2006. Since then, few expeditions returned to the Galapagos Rift. Here, we revisited several Galapagos vents including recently confirmed high-temperature sites and inactive sulfide mounds. From our collecting efforts and observations, as well as revisions from the literature, we update the faunal list to 92 species including 15 new records, restricted to obvious vent associates. Accurate regional faunal lists are important for understanding the biogeography of vent fauna, and our list will also be valuable for setting management strategies.

zoology↗

bioRxiv2022

Hydrothermal Vent Species Assemblage Networks Identify Regional Connectivity Patterns in the Northwest Pacific

The distribution of species among spatially isolated habitat patches supports regional biodiversity and stability, so understanding the underlying processes and structure is a key target of conservation. Although multivariate statistics can infer the connectivity processes driving species distribution, such as dispersal and habitat suitability, they rarely explore structure. Methods from graph theory, applied to distribution data, give insights into both connectivity pathways and processes by intuitively formatting the data as a network of habitat patches. We apply these methods to empirical data from the hydrothermal vent habitats of the Northwest Pacific. Hydrothermal vents are oases of biological productivity and endemicity on the seafloor that are imminently threatened by anthropogenic disturbances with unknown consequences to biodiversity. Here, we describe the structure of hydrothermal vent species assemblage networks, how local and regional parameters affect their structure, and the implications this has for conservation. Two complementary networks were formed from an extensive species assemblage dataset: a bipartite network of species nodes linked to vent site nodes at which they are present, and a similarity network of vent site nodes linked by weighted edges based on their pairwise assemblage similarity. Using these networks, we assessed the role of individual vent sites in linking their network and identified biogeographic sub-regions. The three sub-regions and two outlying sites are separated by their spatial arrangement and local environmental filters. Both networks detected vent sites that play a disproportionately important role in regional pathways, while the bipartite network also identified key vent sites maintaining the distinct species assemblages of their sub-regions. These regional connectivity pathways provide insights into historical colonisation routes, while sub-regional connectivity pathways are of value when selecting sites for conservation and/or estimating the multi-vent impacts from proposed deep-sea mining.

ecology↗