On the genus Crossaster (Echinodermata, Asteroidea) and its distribution

publishedVersio

First in situ observations of the free-floating gelatinous matrix of blackbelly rosefish Helicolenus dactylopterus (Delaroche, 1809)

Reproductive mode in blackbelly rosefish, Helicolenus dactylopterus, has been debated since around 1900, and to our knowledge, there is no previous report on free-floating egg masses of H. dactylopterus. Some authors claim a viviparous strategy, others oviparous, or that the species displays a zygoparous or embryoparous form of oviparity. The most recent publications (ovarian studies) consider H. dactylopterus as zygoparous due to release of developing zygotes in the early phases of development. We report on the first free-floating, gelatinous egg mass matrices of H. dactylopterus, observed in situ. The first egg matrix was observed from Haganes, Bergen, Norway on 10 April 2020, at 20 cm depth. Live eggs were mostly of the same size (∼1 mm), and at late blastula stage. Ethanol-preserved eggs were obtained for DNA barcoding, employing sequences from the cytochrome c oxidase subunit I gene (COI). COI showed 100% similarity with sequences of adult H. dactylopterus. The second egg matrix was observed from Drengevika, Sveio on 12 April 2021, while diving at 15 m depth. Helicolenus dactylopterus is previously known for internal fertilization, and the in situ observations of these free-floating matrices, including embryos at late blastula stage, confirms theories of a zygoparous strategy.</p

In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Cephalopoda, Mollusca)

In total, 90 gelatinous spheres, averaging one meter in diameter, have been recorded from ~ 1985 to 2019 from the NE Atlantic Ocean, including the Mediterranean Sea, using citizen science. More than 50% had a dark streak through center. They were recorded from the surface to ~ 60–70 m depth, mainly neutrally buoyant, in temperatures between 8 and 24°C. Lack of tissue samples has until now, prohibited confirmation of species. However, in 2019 scuba divers secured four tissue samples from the Norwegian coast. In the present study, DNA analysis using COI confirms species identity as the ommastrephid broadtail shortfin squid Illex coindetii (Vérany, 1839); these are the first confirmed records from the wild. Squid embryos at different stages were found in different egg masses: (1) recently fertilized eggs (stage ~ 3), (2) organogenesis (stages ~ 17–19 and ~ 23), and (3) developed embryo (stage ~ 30). Without tissue samples from each and every record for DNA corroboration we cannot be certain that all spherical egg masses are conspecific, or that the remaining 86 observed spheres belong to Illex coindetii. However, due to similar morphology and size of these spheres, relative to the four spheres with DNA analysis, we suspect that many of them were made by I. coindetii.publishedVersio

S3_gelatinous sphere, ommastrephid squid_harald pedersen

MBRJ-2018-0043.R

Correction: On the genus Crossaster (Echinodermata: Asteroidea) and its distribution.

[This corrects the article DOI: 10.1371/journal.pone.0227223.]

Archives du Mus\ue9um national d\u27histoire naturelle

ser.6:t.15 (1938

Starfish (Asteroidea, Echinodermata) from Iceland; spatial distribution and abundance

The Benthic Invertebrates of Icelandic Waters programme (BIOICE) was conducted between 1991 and 2004, for the purpose of gathering specimens within the Icelandic Exclusive Economic Zone (59° 58′N – 69° 35‘N and 30° 52’W – 5° 34′W). In total 12961 asteroid specimens were collected from 654 sampling stations, which comprises 63% of all sampling stations. Sampling depths were between 20 and 2700 m. Total recorded asteroids for Iceland now include 64 species from 21 families and 45 genera, including 23 new species added from this study. The most abundant asteroids collected by BIOICE were Pontaster tenuispinus, Bathybiaster vexillifer and Henricia pertusa group. Maximum species richness was found at depths 100–200 m and 400–500 m, located above the cold Norwegian Sea Deep Water (−1 °C). 24 of the species were recorded at an abundance-weighted mean depth below 1300 m. The area south of the Greenland-Scotland Ridge (GS-Ridge) was more species rich than north of the ridge. Specimens within the rare Myxasteridae family were recorded. A nonmetric multidimensional scaling (NMDS) converged fast from multiple starting points with stress = 0.18. All five abiotic factors (depth, temperature, salinity, latitude and longitude) were strongly related to two of the NMDS ordination axis. The first ordination axis scores had strongest correlation with depth (r = 0.84), whereas the second ordination axis scores had strongest correlation with latitude (r = 0.71)

S5_gelatinsphere_Renault helstroffer

MBRJ-2018-0043.R

A new deepwater species of Calliopiidae, Halirages helgae (Crustacea, Amphipoda), with a synoptic table to Halirages species from the northeast Atlantic

Halirages helgae sp. nov. is recorded from the shelf slopes of the Norwegian Sea at depths of 1000 to 2600 m in the Arctic cold water masses. A total of 50 specimens were found at five stations. The species differs from other known species in the genus Halirages Boeck, 1871 by the bilobed posterior margin of pereonite 7. A synoptic table to the northeast Atlantic species of Halirages is provided