Deep-water Genus Research Articles

Shallow-water Rissoidae of the genera Alvania Risso, 1826, Haurakia Iredale, 1915, Parashiela Laseron, 1956, Simulamerelina Ponder, 1985 and Subestea Cotton, 1944 (Gastropoda, Caenogastropoda, Rissooidea) from French Polynesia, with the description of a new deep-water genus

Shallow-water Rissoidae of the genera Alvania Risso, 1826, Haurakia Iredale, 1915, Parashiela Laseron, 1956, Simulamerelina Ponder, 1985 and Subestea Cotton, 1944 (Gastropoda, Caenogastropoda, Rissooidea) from French Polynesia, with the description of a new deep-water genus

How long have we been mistaken? Multi-tools shedding light into the systematics of the widespread deep-water genus Madrepora Linnaeus, 1758 (Scleractinia)

Deep-water coral reefs are found worldwide and harbor biodiversity levels that are comparable to their shallow-water counterparts. However, the genetic diversity and population structure of deep-water species remain poorly explored, and historical taxonomical issues still need to be resolved. Here we used microsatellite markers as well as ultraconserved elements (UCE) and exons to shed light on the population structure, genetic diversity, and phylogenetic position of the genus Madrepora, which contains M. oculata, one of the most widespread scleractinian species. Population structure of 107 samples from three Southwestern Atlantic sedimentary basins revealed the occurrence of a cryptic species, herein named M. piresae sp. nov. (authored by Kitahara, Capel and Zilberberg), which can be found in sympatry with M. oculata. Phylogeny reconstructions based on 134 UCEs and exon regions corroborated the population genetic data, with the recovery of two well-supported groups, and reinforced the polyphyly of the family Oculinidae. In order to better accommodate the genus Madrepora, while reducing taxonomical confusion associated with the name Madreporidae, we propose the monogeneric family Bathyporidae fam. nov. (authored by Kitahara, Capel, Zilberberg and Cairns). Our findings advance the knowledge on the widespread deep-water genus Madrepora, resolve a long-standing question regarding the phylogenetic position of the genus, and highlight the need of a worldwide review of the genus.

First Finding of Larvae of an Undescribed Species of the Genus Lyconus (Lyconidae) in the North Pacific Ocean

The first illustrated description of two larvae of the rare deep-water genus Lyconus from the North Pacific Ocean has been given. The studied specimens differ from the previously described larvae of L. pinnatus in complete and uniform pigmentation of the body. The new materials complement the existing ideas about the geographical distribution of representatives of the family Lyconidae – this is their first finding in the waters of the Pacific Ocean.

A new species, Sursamucro rostratus sp. nov. (Copepoda, Calanoida) from the abyss of the northern Pacific and South Atlantic

Abstract A new calanoid copepod, Sursamucro rostratus sp. nov., belonging to the family Aetideidae, is described from female specimens collected in the northern Pacific and South Atlantic from abyssal waters close to the sea bed. The new species is the second of a rare deep-water genus, Sursamucro; it differs from its congener in size, configuration of the rostrum, the shape of the posterior corners of the prosome and details of antenna, mandible, maxillule and P1 setation. The genus Sursamucro is recorded for the first time from the northern Pacific and the Atlantic Ocean.

Deep-water lithodids of the genus Paralomis White, 1856 (Decapoda, Anomura, Lithodidae) off western Mexico

Abstract Three species of the deep-water genus Paralomis White, 1856, are reported from western Mexico, two of these for the first time: Paralomis aspera Faxon, 1893, previously known from Panama to Peru, and P. otsuae Wilson, 1990, previously known only from Chile. The third species, P. multispina (Benedict, 1895), has numerous records in the eastern Pacific, particularly off California. Information related to the habitat of each species is provided.

Tindaria kretensis n. sp., a new deep water protobranch (Bivalvia) from the Early Pliocene of Crete (Southern Greece)

Tindaria kretensis n. sp., a minute deep-water protobranch, is described from Early Pliocene marls cropping out in the Voutes section, northern Crete Island. This is one of the few fossil records of Tindaria from the Mediterranean area, the first well documented for the Neogene. Tindaria is an almost cosmopolitan deep-water genus, absent from the modern Mediterranean. Its occurrence in the Early Pliocene is in agreement with what is known about the past psychrospheric conditions in the Mediterranean.

Reassessment of the classification of Bryopsidales (Chlorophyta) based on chloroplast phylogenomic analyses

The Bryopsidales is a morphologically diverse group of mainly marine green macroalgae characterized by a siphonous structure. The order is composed of three suborders – Ostreobineae, Bryopsidineae, and Halimedineae. While previous studies improved the higher-level classification of the order, the taxonomic placement of some genera in Bryopsidineae (Pseudobryopsis and Lambia) as well as the relationships between the families of Halimedineae remains uncertain. In this study, we re-assess the phylogeny of the order with datasets derived from chloroplast genomes, drastically increasing the taxon sampling by sequencing 32 new chloroplast genomes. The phylogenies presented here provided good support for the major lineages (suborders and most families) in Bryopsidales. In Bryopsidineae, Pseudobryopsis hainanensis was inferred as a distinct lineage from the three established families allowing us to establish the family Pseudobryopsidaceae. The Antarctic species Lambia antarctica was shown to be an early-branching lineage in the family Bryopsidaceae. In Halimedineae, we revealed several inconsistent phylogenetic positions of macroscopic taxa, and several entirely new lineages of microscopic species. A new classification scheme is proposed, which includes the merger of the families Pseudocodiaceae, Rhipiliaceae and Udoteaceae into a more broadly circumscribed Halimedaceae, and the establishment of tribes for the different lineages found therein. In addition, the deep-water genus Johnson-sea-linkia, currently placed in Rhipiliopsis, was reinstated based on our phylogeny.

First record of Alternatipathes bipinnata (Cnidaria: Antipatharia) in the Southern Hemisphere

Antipatharians are still poorly documented in the southeastern Pacific, with just eleven species reported in Chilean waters, all of them distributed in subtidal areas from 70 to 2000 m depth (Häussermann & Försterra, 2007; Cañete & Häussermann, 2012; Araya et al. 2016a). Among the family Schizopathidae Brook, 1889, which is characterized by polyps elongated in the direction of the axis and having a transverse diameter of 2 mm or more (Opresko, 2002), the recently described deep-water genus Alternatipathes Molodtsova & Opresko, 2017, encompasses two recognized species, Alternatipathes alternata (Brook, 1889), reported from abyssal basins (2670 to 5089 m depth) of the Indian and Pacific Oceans, and Alternatipathes bipinnata (Opresko, 2005), known from a few specimens collected in deep waters (1130 to 2846 m) off the Pacific coasts of northern Mexico and southern USA (Opresko, 2005; Molodtsova & Opresko, 2017).

A study of the sharks and rays from the Lillebælt Clay (Early–Middle Eocene) of Denmark, and their palaeoecology

Elasmobranch assemblages from the Eocene Lillebælt Clay Formation (Late Ypresian to Middle Lutetian) at Trelde Næs in Denmark yielded teeth of 31 different genera/species from surface collecting as well as from bulk sampling. The fauna is dominated by lamniform pelagic sharks and deepwater genera like Hexanchiformes, Centrophorus, Isistius, Echinorhinus and Pristiophorus. Coupatezia miretrainensis, Centrophorus aff. granulosus and Chlamydoselachus cf. fiedleri are reported for the first time from the Ypresian. The record of Coupatezia miretrainensis extends its stratigraphic record from the Lutetian back to the Late Ypresian, whereas the record of Centrophorus aff. granulosus extends the origin of the Centrophorus granulosus group back to the Late Ypresian from its hitherto known origin in the Lutetian. The possible presence of the sparsely known Bartonian genus Turania awaits further sampling to be confirmed. The Ichthyofauna suggests deposition in a deep-water environment in subtropical to temperate waters on the middle or outer continental shelf and upper slope at water depth down to 350 m. This is in agreement with depositional depths inferred from fossil molluscs and fish otoliths from Trelde Næs.

Deep-sea origin and in-situ diversification of chrysogorgiid octocorals.

The diversity, ubiquity and prevalence in deep waters of the octocoral family Chrysogorgiidae Verrill, 1883 make it noteworthy as a model system to study radiation and diversification in the deep sea. Here we provide the first comprehensive phylogenetic analysis of the Chrysogorgiidae, and compare phylogeny and depth distribution. Phylogenetic relationships among 10 of 14 currently-described Chrysogorgiidae genera were inferred based on mitochondrial (mtMutS, cox1) and nuclear (18S) markers. Bathymetric distribution was estimated from multiple sources, including museum records, a literature review, and our own sampling records (985 stations, 2345 specimens). Genetic analyses suggest that the Chrysogorgiidae as currently described is a polyphyletic family. Shallow-water genera, and two of eight deep-water genera, appear more closely related to other octocoral families than to the remainder of the monophyletic, deep-water chrysogorgiid genera. Monophyletic chrysogorgiids are composed of strictly (Iridogorgia Verrill, 1883, Metallogorgia Versluys, 1902, Radicipes Stearns, 1883, Pseudochrysogorgia Pante & France, 2010) and predominantly (Chrysogorgia Duchassaing & Michelotti, 1864) deep-sea genera that diversified in situ. This group is sister to gold corals (Primnoidae Milne Edwards, 1857) and deep-sea bamboo corals (Keratoisidinae Gray, 1870), whose diversity also peaks in the deep sea. Nine species of Chrysogorgia that were described from depths shallower than 200 m, and mtMutS haplotypes sequenced from specimens sampled as shallow as 101 m, suggest a shallow-water emergence of some Chrysogorgia species.

Loss of planktotrophy and speciation: geographical fragmentation in the deep-water gastropod genus Bathytoma (Gastropoda, Conoidea) in the western Pacific

Dispersal capabilities are crucial in how speciation patterns are determined in marine invertebrates. Species possessing a long-living planktonic larva apparently have a dispersal advantage over those with non-planktotrophic development, and their distant populations may exchange genetic material, maintaining a broad geographical range for the species. Recent species of the gastropod genus Bathytoma (Conoidea) are all characterized by non-planktotrophic development, having most probably lost a free-swimming larva in the pre-Pliocene, as Miocene fossils have protoconchs indicating planktotrophic larval development. All have a bathyal distribution (100–1500 m), which implies that their capability for direct expansion on the bottom is restricted by both deep-sea basins and shallow-water areas, especially in insular West and South-West Indo-Pacific. Therefore, it can be hypothesized that Bathytoma populations should represent numerous, mostly allopatric taxa restricted to a single or contiguous island groups. We tested this hypothesis using molecular and morphological characters independently. One hundred and thirty-eight specimens from the Philippines, Solomons, Vanuatu, and the Coral Sea were sequenced for one mitochondrial (COI) and one nuclear (ITS2) gene, and 14 operational molecular units were recognized. When these molecular units are overlaid over shell characters, 13 species (11 unnamed) and one form of uncertain status are recognized: three occur in the Philippines, six in the Solomons and one in New Caledonia. Broad distributions (inter-archipelagic) are uncommon (three species). On the whole, the phylogeographic pattern of the diversity in the genus is rather complex and probably also reflects processes of sympatric and fine-scale allopatric speciation, and local extinctions. The eleven new species are described and named.

Phylogeny of the snailfishes (Teleostei: Liparidae) based on molecular and morphological data

Liparidae (snailfishes) is one of the most diverse and abundant fish families in polar and deep-sea habitats. However, the evolution of this family is poorly known because of the rarity of many species and difficulties in scoring morphological characters. We perform phylogenetic analyses of Liparidae using sequences from two mtDNA genes, 16S (585 bp) and cytochrome b (426 bp), and 84 morphological characters from 24 species of Liparidae and 4 species of Cyclopteridae (outgroup). The present study confirms earlier hypotheses that the shallow-water genera, such as Liparis and Crystallichthys, occupy basal positions and that deep-water genera, such as Careproctus, Elassodiscus, Rhinoliparis, Paraliparis, Rhodichthys and Psednos, are increasingly derived. The later two genera form a terminal clade which does not include Paraliparis. The topology shows that the family has undergone a reductive type of evolution, with a gradual loss of characters (e.g. sucking disc/pelvic fins, pseudobranchial filaments, skin spinules). Nectoliparis, which had previously been placed either as the basal most genus or among the most derived genera, are found to occupy the most basal position among the taxa analyzed. This result indicates that the sucking disc has been lost at least twice during the evolution of the Liparidae. The basal position of Nectoliparis is supported by its plesiomorphic otolith morphology, whereas an advanced overgrown otolith ostium, unique among teleosts, is found to be apomorphic for a clade containing the derived genera: Paraliparis, Psednos, Rhinoliparis and Rhodichthys. We also identify the presence of probable nuclear inserts of mitochondrial DNA (Numts) in three species of Careproctus and in Elassodiscus caudatus.

Reproductive isolation among deep‐water cichlid fishes of Lake Malawi differing in monochromatic male breeding dress

Male nuptial colour hues are important for the maintenance of reproductive isolation among cichlid fish species, and environmental changes that lead to narrower light spectra can lead to hybridization. However, cichlid species can naturally co-occur in narrow light spectrum habitats, such as turbid shallow lakes and the deep benthic zones of African rift lakes. Closely related species from narrow light spectrum habitats tend to differ little in the palette of male nuptial colours, thus for these taxa differences in colour patterns may be more important than differences in colour hue for species recognition. To investigate this hypothesis we examined morphometric and genetic differentiation among males of four sympatric putative species within the deep-water genus Diplotaxodon. These taxa live in a narrow-light spectrum environment where only blue light is present, and males differ primarily in 'monochromatic' black, white and silver patterning of the body and fins. Significant genetic differentiation was present among taxa in both microsatellite DNA and mitochondrial DNA, including one pair with no significant morphometric differentiation. Thus, these taxa represent reproductively isolated biological species, a result consistent with male nuptial patterning being important for species recognition and assortative mating. As such, we suggest that narrow-light spectra need not always represent barriers to effective visually mediated mate recognition.

Two new species ofPseudopetigurus (Trilobita) from the Arenig — Llanvirn of South China

Two new species ofPseudopetigurus are described from northern Hunan Province, China.P. deprati n. sp. is abundant in the upper Zitai Formation (upper Arenig) of Shuanghong, Baiyun, Shimen County, andP. expansus n. sp. occurs throughout the Jiuxi Formation (Arenig — lower Llanvirn) of Panjiazui, Taoyuan County. These formations represent outer shelf facies from the Jiangnan Transitional Belt of the South China Plate, close to the southeast margin of the Yangtze Platform. BothP. deprati andP. expansus show similarities to Upper Ordovician species ofPseudopetigurus recorded from South China. Other species ofPseudopetigurus are known almost entirely from cranidia, but pygidia and librigenae are also described for both new species, and the first known hypostome assigned to the genus is described forP. expansus. These two species are ecologically important members of offshore trilobite faunas during the Arenig — Llanvirn and define the outer shelfPseudopetigurus Association of South China. Despite being a deep-water genus,Pseudopetigurus is biogeographically restricted to the western margin of the Gondwanan craton and neighbouring regions of Baltica.

A New Deep-Water Genus and Species of a Branchial Bopyrid Infesting the Galatheid Crab Munidopsis Erinaceus from the Southwestern Gulf of Mexico

A New Deep-Water Genus and Species of a Branchial Bopyrid Infesting the Galatheid Crab Munidopsis Erinaceus from the Southwestern Gulf of Mexico

A new deep-water genus and species of Fabriciinae fanworm (Polychaeta: Sabellidae) from Antarctica

A new deep-water genus and species of Fabriciinae fanworm (Polychaeta: Sabellidae) from Antarctica

Jagtia kunradensis, a new genus and species of clawed lobster (Decapoda: Nephropidae) from the Upper Cretaceous (Upper Maastrichtian) Maastricht Formation, The Netherlands

A new genus and species of clawed lobster, Jagtia kunradensis, is described from the Upper Cretaceous (Upper Maastrichtian) Kunrade Limestone facies of the Maastricht Formation, The Netherlands. Three nephropid lobster genera and at least three species (Oncopareia bredai Bosquet, 1854, sensu Tshudy, 1993, Oncopareia sp. Tshudy, 1993, Hoploparia beyrichi Schlüter, 1862, and Jagtia kunradensis) have now been collected from limestones of the Maastrichtian type area (southeastern Netherlands and northeastern Belgium). Cladistic methods were employed in re-evaluating the phylogenetic relationships of the nephropid lobsters, including Jagtia. These analyses indicate that Jagtia is part of a clade that includes the recent Thymops and Thymopsis. The new genus is the first fossil form to be closely allied with these deep-water genera.

JAGTIA KUNRADENSIS,A NEW GENUS AND SPECIES OF CLAWED LOBSTER (DECAPODA: NEPHROPIDAE) FROM THE UPPER CRETACEOUS (UPPER MAASTRICHTIAN) MAASTRICHT FORMATION, THE NETHERLANDS

Abstract A new genus and species of clawed lobster, Jagtia kunradensis, is described from the Upper Cretaceous (Upper Maastrichtian) Kunrade Limestone facies of the Maastricht Formation, The Netherlands. Three nephropid lobster genera and at least three species (Oncopareia bredai Bosquet, 1854, sensu Tshudy, 1993, Oncopareia sp. Tshudy, 1993, Hoploparia beyrichi Schluter, 1862, and Jagtia kunradensis) have now been collected from limestones of the Maastrichtian type area (southeastern Netherlands and northeastern Belgium). Cladistic methods were employed in re-evaluating the phylogenetic relationships of the nephropid lobsters, including Jagtia. These analyses indicate that Jagtia is part of a clade that includes the recent Thymops and Thymopsis. The new genus is the first fossil form to be closely allied with these deep-water genera.

Oocyte development and gonad production of Nematocarcinus lanceopes (Decapoda: Caridea) in the eastern Weddell Sea, Antarctica

Nematocarcinus lanceopes Bate 1888 is the only decapod that occurs in large numbers on the continental slope of the Weddell Sea, Antarctica. Histological examination of the female gonads and analyses of oocyte growth indicate a biannual reproduction cycle with seasonal occyte maturation in this species. Vitellogenic development is estimated to take 2 years and culminates during summer. Females spawn three times, every 2nd year, while they grow from 27 to 34 mm carapace length. Based on these results the calculated female gonad production is 184 g wet mass (70.5 g dry mass)/total catch, which is high compared to shrimp populations on the continental shelf of the Weddell Sea. Seasonal reproductive patterns of N. lanceopes seem to reflect oscillating food conditions in the Antarctic Weddell Sea. This mode of reproduction differs from all other Nematocarcinidae, which release eggs the whole year round. The ability to adapt the reproductive cycle to a seasonal productivity pattern may have been an important factor in extending the distribution range of the deep-water genus Nematocarcinus into Antarctic waters.

Evaluation of geological age and environmental factors in changing aspects of the terrestrial vertebrate fauna during the Carboniferous

ABSTRACTOf all the localities that have yielded a diversity of Carboniferous tetrapods, the fossil assemblage at East Kirkton most closely resembles that of the Joggins locality in Nova Scotia. Both assemblages are dominated by dendrerpetontid temnospondyls and a smaller number of small anthracosaurs, which are thought to have been primarily terrestrial in habits. Both localities lack adelogyrinids and lysorophids, and such presumably deep water genera as Crassigyrinusand large embolomeres. The East Kirkton Limestone differs in the presence of aïstopods and a possible nectridean, which are associated with a shallow-water environment in other localities. The absence of amniotes and microsaurs may be explained by the later evolution of these groups, their limited geographical distribution, or the lack of any aspects of the depositional environment that would preferentially select primarily terrestrial animals.