Climate change triggers poleward shifts in species distribution leading to changes in biogeography. In the marine environment, fish respond quickly to warming, causing community-wide reorganizations, ...which result in profound changes in ecosystem functioning. Functional biogeography provides a framework to address how ecosystem functioning may be affected by climate change over large spatial scales. However, there are few studies on functional biogeography in the marine environment, and none in the Arctic, where climate-driven changes are most rapid and extensive. We investigated the impact of climate warming on the functional biogeography of the Barents Sea, which is characterized by a sharp zoogeographic divide separating boreal from Arctic species. Our unique dataset covered 52 fish species, 15 functional traits, and 3,660 stations sampled during the recent warming period. We found that the functional traits characterizing Arctic fish communities, mainly composed of small-sized bottom-dwelling benthivores, are being rapidly replaced by traits of incoming boreal species, particularly the larger, longer lived, and more piscivorous species. The changes in functional traits detected in the Arctic can be predicted based on the characteristics of species expected to undergo quick poleward shifts in response to warming. These are the large, generalist, motile species, such as cod and haddock. We show how functional biogeography can provide important insights into the relationship between species composition, diversity, ecosystem functioning, and environmental drivers. This represents invaluable knowledge in a period when communities and ecosystems experience rapid climate-driven changes across biogeographical regions.
In pelagic ecosystems in all oceans, euphausiids (krill) are important components of the zooplankton. In May–June 2019, euphausiids were investigated from temperate to tropical waters along the 110°E ...meridian, originally surveyed in 1962–1963 during the first International Indian Ocean Expedition (IIOE). A total of 28 species of tropical, subtropical and temperate euphausiids were identified from day and night vertical hauls using an Indian Ocean Standard Net (IOSN) through the upper 200 m of the water column between 11.5°S and 39.5°S. Abundances of larvae, juveniles and adults were generally higher in warmer tropical waters, as were the number of species, albeit the highest abundance recorded (4240 inds·1000 m−3), comprising of Thysanoessa gregaria, occurred in the cooler waters south of the Subtropical Front. Species from the genera Stylocheiron and Euphausia dominated along most of the transect line. The different water masses together with the influence of ocean currents appeared to affect the euphausiid assemblages with, for example, the occurrence of the Pacific Ocean species, Euphausia pacifica/nana, likely reaching the study region via the Indonesian Throughflow, and the occurrence of the typically neritic Pseudeuphausia latifrons, likely a result of the westward propagation of Leeuwin Current eddies. Redundancy analysis showed that the properties of water masses had a stronger influence on euphausiid assemblage variability than food availability (chlorophyll a), which was relatively low across most of the transect. In comparison to the first IIOE, which used the same IOSN collection method, a similar number of species was identified from the more temporally extensive sampling period in 1962–1963, though the occurrences of rare species were different. At comparable latitudes during May–June in 1963 and 2019, total euphausiid abundances and proportions of life stages were similar. This rare opportunity to repeat an open ocean transect provides an updated baseline on euphausiid species occurrence, distribution and assemblages in the eastern Indian Ocean.
•Warmer waters support more krill species and typically have higher abundances.•Evidence of swarming of Thysanoessa gregaria south of the Subtropical Front.•Temperature and salinity are key drivers of assemblages and species distributions.•Along 110°E, the species of krill identified were similar between 1962-63 and 2019.
The species classified by various authors as Tertiary relics in the Bulgarian spider fauna are reviewed. The classification criteria used by previous authors are evaluated and discussed, and an ...attempt is made to identify the zoogeographical status of these species. Based upon the arguments presented below, it can be concluded that the existence of spider species with Tertiary origin in the modern Bulgarian spider fauna is highly doubtful.
Systematization of data on Cyclopoida from individual regions is one of the important stages in research into the world fauna of the order. This work aims to compile an up-to-date list of Cyclopoida ...species of Kazakhstan based on a critical analysis and systematization of literature and our data. A generalization of data showed that the water bodies of Kazakhstan are inhabited by 58 species and 1 subspecies of Cyclopoida from 3 families and 19 genera. The largest number of species include the genera Diacyclops (7), Eucyclops (6), Cyclops (4), and Thermocyclops (6). Cyclopoida species richness distribution across zoogeographical provinces of Kazakhstan was relatively uniform.
Abstract
Birds of the Indo-Pacific have provided biologists with many foundational insights. This study presents evidence for strong phylogeographic structure in two sunbird species from the heart of ...this region, the olive-backed sunbird, Cinnyris jugularis, and the black sunbird, Leptocoma aspasia. We assessed population divergence using morphological, plumage, bioacoustic and molecular data (mitochondrial ND2/ND3). Our findings indicate that the olive-backed sunbird should be recognized as multiple species, because birds from Sulawesi and the Sahul Shelf are closely related to each other, but widely separated from those in other regions. In addition, we provide evidence for an endemic species on the Wakatobi Islands, an archipelago of deep-sea islands off south-east Sulawesi. That a small bird could exhibit a range all the way from Sulawesi to Australia, while diverging on a small archipelago within this range, illustrates the complex interplay between dispersal and speciation. Our black sunbird genetic data also suggest unrecognized population structure, despite relatively weak plumage divergence. Black sunbirds in Sulawesi are likely to be a separate species from those in New Guinea, with a mean genetic distance of 9.1%. Current taxonomy suggests these sunbird species transcend classic biogeographic barriers, but our results suggest that these barriers are not easily bypassed.
In the South Atlantic Ocean, the Subtropical Front (STF) separates warm-water copepod assemblages of high diversity from cold-water assemblages of lower diversity. Comparable information from the ...southern Indian Ocean are scarce. Here we test observations made in the southwest sector of the Indian Ocean using samples collected during 2009 from along the South West Indian Ridge (SWIR, ∼27 - 42° S). Distinct assemblages were associated with the Agulhas Return Current (ARC), the Sub-Tropical Front (STF) and Sub-Antarctic Front (SAF). Sixty-nine percent of the structure of the assemblages could be attributable to the temperature at both the surface and 200 m, the salinity and the fluorescence signal of surface waters and the depth of the upper mixed layer. Forty-nine copepod genera and 132 species were recorded. While richness was greatest in waters of the ARC and lowest in the SAF, copepods were most abundant in the latter and scarcest in the former. Mean prosome length decreased with increasing latitude, and assemblages of the ARC included greater numbers of carnivorous taxa than those associated with either the STF or the SAF. As in the Atlantic, the STF markedly influenced the relative distribution range of copepod assemblages above the South West Indian Ridge.
As the most species-rich group of Palaearctic rodents, voles and lemmings are frequently used in various research endeavours of fundamental and applied significance. The present work integrates ...achievements of the genomic era with the traditional taxonomy and provides an authoritative and up-to-date taxonomic guide to the animal group which is of great interest to experts engaged in medical zoology, epidemiology, biostratigraphy, zooarchaeology, evolutionary research, population ecology, animal systematics, biodiversity conservation, museum collection management and many more biological subdisciplines. The text is supplemented by 331 illustrations and over one thousand references. Depicted are morphological details of skull and dentition of each of the 128 species and their distributions are mapped in detail. The book will allow the user to interpret intelligently and cautiously the interrelationships among species of voles and lemmings and to follow the anticipated taxonomic change with a critical eye.
Bemisia tabaci has long been considered a complex species. It rose to global prominence in the 1980s owing to the global invasion by the commonly named B biotype. Since then, the concomitant eruption ...of a group of plant viruses known as begomoviruses has created considerable management problems in many countries. However, an enduring set of questions remains: Is B. tabaci a complex species or a species complex, what are Bemisia biotypes, and how did all the genetic variability arise? This review considers these issues and concludes that there is now sufficient evidence to state that B. tabaci is not made up of biotypes and that the use of biotype in this context is erroneous and misleading. Instead, B. tabaci is a complex of 11 well-defined high-level groups containing at least 24 morphologically indistinguishable species.
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