Natural history collections as a basis for sound biodiversity assessments: Plexauridae (Octocorallia, Holaxonia) of the Naturalis CANCAP and Tyro Mauritania II expeditions

Abstract

Mapping biodiversity is the marathon of the 21st Century as an answer to the present extinction crisis. A century in which science is also characterised by large scientific datasets collected through new technologies aiming to fill gaps in our knowledge of species distributions. However, most species records rely on observations that are not linked to specimens, which does not allow verification of species hypotheses by other scientists. Natural history museums form a verifiable source of biodiversity records which were made by taxonomists. Nonetheless, these museums seem to be forgotten by biologists in scientific fields other than taxonomy or systematics. Naturalis Biodiversity Center (NBC) in Leiden is care keeper of large collections of marine organisms, which were sampled in the Northeast Atlantic during the CANCAP and Tyro Mauritania II expeditions (1976–1988). Many octocorals were sampled and deposited in the NBC collection, where they became available for study and were partially identified by the senior author (M.G.) in the 1980s. Nonetheless, no checklist or taxonomic revision was published so far with the complete results. In 2016 the first author visited NBC to examine NE Atlantic Plexauridae octocorals. Plexauridae octocoral-vouchered records were listed and mapped to reveal high standard primary biodiversity records unreported so far for the NE Atlantic Ocean. Twenty-four Plexauridae species with ~ six putative new species to science were discovered and eleven new biogeographical records were made from distinct Macaronesian archipelagos. Finally, new depth range records were found for three species at sea basin level and for eight species at a regional scale.

Content Aware and Other Case Studies: Museum of Synthetic History

“…The Earth's estimated biodiversity is in the order of 10 million species, from which only 10-20% are currently known to science, while the rest still lacks a name, a description, and basic knowledge of its biology. (Krishtalka and Humphrey 2000;Wilson 2003;Costello et al 2015;Sampaio et al, 2019) The biodiversity extinction crisis is an alarming trend across related fields of science. The rate of biodiversity loss is accelerating, leading to a tendency for "Big Data" production on species observation-based occurrences instead of specimen-based occurrences as a way to map and protect biodiversity (Troudet et al 2018).…”

“…The rate of biodiversity loss is accelerating, leading to a tendency for "Big Data" production on species observation-based occurrences instead of specimen-based occurrences as a way to map and protect biodiversity (Troudet et al 2018). During 300 years of biodiversity exploration, many organisms were collected, catalogued, identified, and stored under a systematic order (Sampaio et al, 2019). However, many samples there are, we're barely reaching a quarter of well-documented observable species on Earth, which form the basis of this datadriven research.…”

“…All of which, in turn, results in a doubtful source of knowledge for future generations. (Troudet et al 2018;Sampaio et al, 2019) In other words, in writing the history of life on earth we're currently limiting ourselves to recycling only the existing data in a feedback loop machine of widely available and trending computational methods, such as datadriven and AI-powered research technics. This is an alarming trend in varying fields and within any application of AI since a dataset will never be truly complete.…”

The Mauritanian Slope (NE Atlantic) Has No Desert:Swiftia phaeton(Holaxonia: Plexauridae) Shaping Coral Gardens

“…Octocoral gardens seem to be widespread throughout the NE Atlantic Ocean from the Hardangerfjord in Norway to the Mid-Atlantic Ridge (MAR) and island slopes and seamounts of the Azores; and in the Mediterranean Sea [5,7,[33][34][35]. In this area, colonies of three species of the genus Swiftia Duchassaing and Michelotti, 1864 [91] were mostly found to be sparsely distributed and associated with hard substrates, between 20 and 2400 m depth [36,37]. Nonetheless, Swiftia dubia (as S. pallida Madsen, 1970 [101]) is considered a dominant species of the "cold-water gorgonians on hard/mixed substrate or compact mud" category of the CoralFISH cold-water coral biotope classification scheme, indicating the presence of Swiftia coral gardens in the area [22].…”

A new octocoral species of Swiftia (Holaxonia, Plexauridae) from the upper bathyal off Mauritania (NE Atlantic)

“…Octocorals from Mauritania were mostly known from shallower depths, dominated by species of the genus Leptogorgia Milne Edwards, 1857 (Grasshoff 1986(Grasshoff , 1988. The few octocorals recorded at deeper (> 200 m) Mauritanian waters were sea pens, acanthogorgiids, and plexaurids (Grasshoff 1981;Buschewski 2016;Ramos et al 2017c;Sampaio et al 2019). Worldwide bathymetrical records of the family Plexauridae Gray, 1859 are from 20 to 3000 m depth in tropical, temperate, and polar waters (Bayer and Weinheimer 1974;Grasshoff 1977Grasshoff , 1985Grasshoff , 1992López-González 2006;Breedy et al 2019;Sampaio et al 2019).…”