Background A principal function of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is to “perform regular and timely assessments of knowledge on biodiversity.” In December 2013, its second plenary session approved a program to begin a global assessment in 2015. The Convention on Biological Diversity (CBD) and five other biodiversity-related conventions have adopted IPBES as their science-policy interface, so these assessments will be important in evaluating progress toward the CBD’s Aichi Targets of the Strategic Plan for Biodiversity 2011–2020. As a contribution toward such assessment, we review the biodiversity of eukaryote species and their extinction rates, distributions, and protection. We document what we know, how it likely differs from what we do not, and how these differences affect biodiversity statistics. Interestingly, several targets explicitly mention “known species”—a strong, if implicit, statement of incomplete knowledge. We start by asking how many species are known and how many remain undescribed. We then consider by how much human actions inflate extinction rates. Much depends on where species are, because different biomes contain different numbers of species of different susceptibilities. Biomes also suffer different levels of damage and have unequal levels of protection. How extinction rates will change depends on how and where threats expand and whether greater protection counters them. Different visualizations of species biodiversity. ( A ) The distributions of 9927 bird species. ( B ) The 4964 species with smaller than the median geographical range size. ( C ) The 1308 species assessed as threatened with a high risk of extinction by BirdLife International for the Red List of Threatened Species of the International Union for Conservation of Nature. ( D ) The 1080 threatened species with less than the median range size. (D) provides a strong geographical focus on where local conservation actions can have the greatest global impact. Additional biodiversity maps are available at www.biodiversitymapping.org. Advances Recent studies have clarified where the most vulnerable species live, where and how humanity changes the planet, and how this drives extinctions. These data are increasingly accessible, bringing greater transparency to science and governance. Taxonomic catalogs of plants, terrestrial vertebrates, freshwater fish, and some marine taxa are sufficient to assess their status and the limitations of our knowledge. Most species are undescribed, however. The species we know best have large geographical ranges and are often common within them. Most known species have small ranges, however, and such species are typically newer discoveries. The numbers of known species with very small ranges are increasing quickly, even in well-known taxa. They are geographically concentrated and are disproportionately likely to be threatened or already extinct. We expect unknown species to share these characteristics. Current rates of extinction are about 1000 times the background rate of extinction. These are higher than previously estimated and likely still underestimated. Future rates will depend on many factors and are poised to increase. Finally, although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity. Outlook Progress on assessing biodiversity will emerge from continued expansion of the many recently created online databases, combining them with new global data sources on changing land and ocean use and with increasingly crowdsourced data on species’ distributions. Examples of practical conservation that follow from using combined data in Colombia and Brazil can be found at www.savingspecies.org and www.youtube.com/watch?v=R3zjeJW2NVk.

The biodiversity of species and their rates of extinction, distribution, and protection

Proceedings of the Academy of Natural Sciences of Philadelphia

Marine plankton support global biological and geochemical processes. Surveys of their biodiversity have hitherto been geographically restricted and have not accounted for the full range of plankton size. We assessed eukaryotic diversity from 334 size-fractionated photic-zone plankton communities collected across tropical and temperate oceans during the circumglobal Tara Oceans expedition. We analyzed 18S ribosomal DNA sequences across the intermediate plankton-size spectrum from the smallest unicellular eukaryotes (protists, >0.8 micrometers) to small animals of a few millimeters. Eukaryotic ribosomal diversity saturated at ~150,000 operational taxonomic units, about one-third of which could not be assigned to known eukaryotic groups. Diversity emerged at all taxonomic levels, both within the groups comprising the ~11,200 cataloged morphospecies of eukaryotic plankton and among twice as many other deep-branching lineages of unappreciated importance in plankton ecology studies. Most eukaryotic plankton biodiversity belonged to heterotrophic protistan groups, particularly those known to be parasites or symbiotic hosts.

/pdf/eukaryotic-plankton-diversity-in-the-sunlit-ocean-pxea35iar7.pdf

Eukaryotic plankton diversity in the sunlit ocean

– An annotated checklist of the extant brachyuran crabs of the world is presented for the first time. Over 10,500 names are treated including 6,793 valid species and subspecies (with 1,907 primary synonyms), 1,271 genera and subgenera (with 393 primary synonyms), 93 families and 38 superfamilies. Nomenclatural and taxonomic problems are reviewed in detail, and many resolved. Detailed notes and references are provided where necessary. The constitution of a large number of families and superfamilies is discussed in detail, with the positions of some taxa rearranged in an attempt to form a stable base for future taxonomic studies. This is the first time the nomenclature of any large group of decapod crustaceans has been examined in such detail.

/pdf/systema-brachyurorum-part-1-an-annotated-checklist-of-extant-4dzctv9k63.pdf

Systema Brachyurorum: Part 1. An Annotated checklist of extant brachyuran crabs of the world

https://www.cell.com/current-biology/pdf/S0960-9822(12)01138-4.pdf

The magnitude of global marine species diversity

Systematics and classification of Brachyura

A new species of freshwater crab, Austrothelphusa gilbertensis, is described from Gilbert River Catchment, north-western Queensland. It is morphologically most similar to A. wasselli Bishop, 1963, described from the eastward flowing Stewart Drainage Basin, much further to the north-east on Cape York. It differs from A. wasselli by several morphological characters including, better defined gastro-cardiac carapace grooves, cervical groove relatively deeper, postfrontal lobes more prominent and bearing striated crests, larger and fewer spots on carapace and legs, epibranchial tooth more prominent, walking legs more slender, and G1 more strongly curved. A CO1 genetic divergence of greater than 6% confirms its novel status. Intraspecific CO1 divergence within catchments is also discussed.

/pdf/redescription-of-austrothelphusa-wasselli-bishop-1963-3nb40809x3.pdf

Redescription of Austrothelphusa wasselli (Bishop, 1963) (Crustacea: Brachyura: Gecarcinucidae), and designation of a new species from the Gilbert River, north Queensland, Australia.

The status of two poorly known fiddler crabs, Uca iranica Pretzmann, 1971, from the Persian Gulf, and U. albimana (Kossmann, 1877), from the Red Sea, was studied using two mitochondrial genes: the large subunit (16S) ribosomal (r)RNA and cytochrome oxidase subunit I (COI). A molecular phylogeny shows both U. iranica and U. albimana to be members of a monophyletic U. lactea species-complex containing six taxa, with three highly supported internal clades. Uca iranica and U. albimana are the closest genetically, but are different enough to be considered valid species (16S rRNA nucleotide divergence > 7.0%, and COI > 11.9%), and form a highly supported “western” clade with U. annulipes (in line with the original morphological concept). A West Pacific “eastern” clade includes U. lactea in the north and the more widely ranging U. perplexa. An Australian endemic species, U. mjoebergi, forms a third monotypic clade.

Genetic evidence for the recognition of two fiddler crabs, Uca iranica and U. albimana (Crustacea: Brachyura: Ocypodidae), from the northwestern Indian Ocean, with notes on the U. lactea species-complex

The Asian soldier crab Mictyris brevidactylus Stimpson, 1858, was re-examined genetically and morphologically from specimens collected across its range. It was found to consist of two cryptic sister species, with crabs from the Ryukyu Islands representing a new species, M. guinotae. Mictyris guinotae is smaller at maturity than M. brevidactylus, has plain blue colouring without red banding on the legs, and has a differently shaped apex of its male first gonopod. The two species also differ genetically, with 16S rRNA and COI showing a mean divergence (K2P distance) of 1.08% and 4.39%, respectively, representing 2.0 and 3.5 times more divergence than present intraspecifically. Results provide further evidence that some elements of the marine fauna of the Ryukyu Islands have had a separate evolutionary history from continental Asia as well as Taiwan.

/pdf/a-new-species-of-mictyris-decapoda-brachyura-mictyridae-from-4bq70yskar.pdf

A New Species Of Mictyris (Decapoda, Brachyura, Mictyridae) From The Ryukyu Islands, Japan

A new family, Xenograpsidae, is established to include an unusual genus of grapsoid crabs, Xenograpsus Takeda & Kurata, 1977, associated with shallow hydrothermal vents in the western Pacific Ocean While Xenograpsus is related to other grapsoid crabs such as the Grapsidae, Varunidae, Sesarmidae, Gecarcinidae, and Plagusiidae, evidence from adult and larval morphology and DNA analyses show that the separation between lineages is very deep, and that it should be regarded as belonging to a distinct family Key morphological differences relate to the structure of the sternum, orbit, basal antennal segment, shape of third maxillipeds, and gonopore position The relationships amongst the grapsoid families, as currently conceived, are also briefly discussed

Xenograpsidae, a new family of grapsoid crabs (crustacea: brachyura) associated with shallow water hydrothermal vents

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Peter J. F. Davie

Author Tools

Chat about Author