Demersal fish and decapod crustacean fauna of the upper continental slope off Nova Scotia from LaHave to St. Pierre Banks

1988 ◽  
Vol 66 (9) ◽  
pp. 1952-1960 ◽  
Author(s):  
Douglas F. Markle ◽  
Michael J. Dadswell ◽  
Ralph G. Halliday

Four 200-m depth strata were sampled for fish and decapod crustaceans on the upper continental slope (400–1200 m) off Nova Scotia. There was more-or-less continuous replacement of fish fauna with depth. Numerically dominant fishes in the upper two strata (< 800 m) were Sebastes spp., Phycis chesteri, and Glyptocephalus cynoglossus. Predominant fishes in the lower two strata (> 800 m) were Centroscyllium fabricii, Synaphobranchus kaupii, and Coryphaenoides rupestris. Nezumia bairdii was relatively abundant throughout the depth range sampled. The ichthyofauna of the upper slope was similar to that off the Middle Atlantic States and off Newfoundland at comparable depths, but qualitative differences existed in losses of some and additions of other species. Dominant decapod crustaceans in the shallowest stratum (200–400 m) were Pontophilus norvegicus, Plesiopenaeus edwardsianus, and Panalus propinquus. This stratum appeared to be a transition zone between shelf and slope decapod faunas. More species occurred and at higher densities in the deeper strata; predominant were Acanthephyra spp., Pasiphaea tarda, Metacrangon jacqueti, and Sabinea hystrix. The decapod fauna off Nova Scotia is similar to that of the mid-Atlantic Bight but less diverse.

Author(s):  
Lina M. Saavedra Díaz ◽  
Adela Roa Varón ◽  
Arturo Acero P. ◽  
Luz Stella Mejía

Five cruises were made between October 1998 and April 1999 in order to improve the knowledge about the fish fauna of the upper continental slope in the Colombian Caribbean, as a part of the project “INVEMAR MACROFAUNA I”. A total of 80 trawls were made during five cruises between October of 1998 and April of 1999, distributed along of the ecoregions of Guajira, Palomino, Tayrona , Magdalena, Morrosquillo, and Darién, along the continental slope of the Colombian Caribbean between 200 and 525 m depth using a semi-balloon trawling net. Nineteen species of the orders Albuliformes, Anguilliformes, Osmeriformes, Stomiiformes, Ateleopodiformes, Aulopiformes and Pleuronectiformes are reported for the first time from Colombian waters, and the presence of two others is ratified. The results show a first report for the Caribbean, three first reports for the Southern Caribbean, and 15 first reports for the Colombian Caribbean. The data extend the depth range of two species and the maximum size of another one.


2016 ◽  
Vol 67 (5) ◽  
pp. 471-494 ◽  
Author(s):  
Matúš Hyžný

AbstractDecapod associations have been significant components of marine habitats throughout the Cenozoic when the major diversification of the group occurred. In this respect, the circum-Mediterranean area is of particular interest due to its complex palaeogeographic history. During the Oligo-Miocene, it was divided in two major areas, Mediterranean and Paratethys. Decapod crustaceans from the Paratethys Sea have been reported in the literature since the 19thcentury, but only recent research advances allow evaluation of the diversity and distribution patterns of the group. Altogether 176 species-level taxa have been identified from the Oligocene and Miocene of the Western and Central Paratethys. Using the three-dimensional NMDS analysis, the composition of decapod crustacean faunas of the Paratethys shows significant differences through time. The Ottnangian and Karpatian decapod associations were similar to each other both taxonomically and in the mode of preservation, and they differed taxonomically from the Badenian ones. The Early Badenian assemblages also differed taxonomically from the Late Badenian ones. The time factor, including speciation, immigration from other provinces and/or (local or global) extinction, can explain temporal differences among assemblages within the same environment. High decapod diversity during the Badenian was correlated with the presence of reefal settings. The Badenian was the time with the highest decapod diversity, which can, however, be a consequence of undersampling of other time slices. Whereas the Ottnangian and Karpatian decapod assemblages are preserved virtually exclusively in the siliciclastic “Schlier”-type facies that originated in non-reefal offshore environments, carbonate sedimentation and the presence of reefal environments during the Badenian in the Central Paratethys promoted thriving of more diverse reef-associated assemblages. In general, Paratethyan decapods exhibited homogeneous distribution during the Oligo-Miocene among the basins in the Paratethys. Based on the co-occurrence of certain decapod species, migration between the Paratethys and the North Sea during the Early Miocene probably occurred via the Rhine Graben. At larger spatial scales, our results suggest that the circum-Mediterranean marine decapod taxa migrated in an easterly direction during the Oligocene and/or Miocene, establishing present-day decapod communities in the Indo-West Pacific.


Author(s):  
David J. Hughes

Bryozoans were collected from nine stations between 569 and 1278 m depth on the Hebridean continental slope north-west of Lewis. The 21 species recorded from 1544 colonies included three species new to the British fauna. The bryozoan fauna, growing on pebbles, cobbles and small boulders, was dominated by species with encrusting, spot or ribbon-like colony morphologies. The few erect species were rare. Colony density on available rock substrata declined from 569 to 855 m, but was high at 1278 m, where the nodular species Turbicellepora boreale occurred on pebbles as small as 1 cm diameter. Cyclostomates made up >90% of the colonies in the shallowest sample and were present in lower numbers to 855 m. None were recorded at 1278 m. In the 569–855 m depth range, diversity and evenness were lowest at 569 m but relatively constant at the other stations. A species accumulation curve suggests that the 20 species recorded is a good estimate of the total fauna in this depth range.


Parasitology ◽  
1998 ◽  
Vol 116 (1) ◽  
pp. 73-83 ◽  
Author(s):  
D. J. MARCOGLIESE ◽  
D. K. CONE

Species richness and diversity of macroparasite assemblages were compared among American eels (Anguilla rostrata) from Nova Scotia, European eels (A. anguilla) from the United Kingdom (Kennedy, Bush & Aho, 1986; Esch et al. 1988; Kennedy, 1990, 1993), and Australian eels (A. reinhardtii) from Queensland (Kennedy, 1995). Community richness and diversity of the macroparasite fauna of American and European eels did not differ significantly for total parasite component communities, intestinal parasite component communities, and intestinal parasite infracommunities. The similarities in richness and diversity between the parasite communities of American and European eels are not surprising given the common, recent origin of these sister species. However, differences in species composition were noted between Nova Scotia and the UK. Both species of eels were infected by a nearly identical suite of specialists, but differences occurred in the species number and composition of generalist parasites. In addition, generalist species were rarely dominant in Nova Scotia, but commonly so in the UK. These differences can be attributed to the differences in the freshwater fish fauna and their parasites that occur between Nova Scotia and the UK. American and European eels are derived from a common ancestor and, whereas they have carried with them a common suite of specialist parasites during their brief period of independence, they acquired different suites of generalists apparently from their respective continental faunas after they diverged. In contrast, parasite communities of American and European eels were significantly less diverse and speciose than those of Australian eels regardless of scale (total component community, intestinal component community, intestinal infracommunity). These results support the notion that parasite communities have had more time to evolve and/or that tropical conditions have promoted parasite speciation in Australian eels.


2000 ◽  
Vol 12 (3) ◽  
pp. 276-287 ◽  
Author(s):  
Joseph T. Eastman

Antarctica is a continental island and the waters of its shelf and upper slope are an insular evolutionary site. The shelf waters resemble a closed basin in the Southern Ocean, separated from other continents by distance, current patterns and subzero temperatures. The benthic fish fauna of the shelf and upper slope of the Antarctic Region includes 213 species with higher taxonomic diversity confined to 18 families. Ninety-six notothenioids, 67 liparids and 23 zoarcids comprise 45%, 32% and 11% of the fauna, a combined total of 88%. In high latitude (71–78°S) shelf areas notothenioids dominate abundance and biomass at levels of 90–95%. Notothenioids are also morphologically and ecologically diverse. Although they lack a swim bladder, the hallmark of the notothenioid radiation has been repeated diversification into water column habitats. There are pelagic, semipelagic, cryopelagic and epibenthic species. Notothenioids exhibit the disproportionate speciosity and high endemism characteristic of fish species flock. Antifreeze glycopeptides originating from a transformed trypsinogen gene are a key innovation. It is not known when the modern Antarctic shelf fauna assumed its current taxonomic composition. A late Eocene fossil fauna was taxonomically diverse and cosmopolitan. There was a subsequent faunal replacement with little carryover of families into the modern fauna. Basal notothenioid clades probably diverged in Gondwanan shelf locations during the early Tertiary. Dates inferred from molecular sequences suggest that phyletically derived Antarctic clades arose 15–5 m.y.a.


2019 ◽  
Vol 59 (2) ◽  
pp. 319-320
Author(s):  
N. N. Dmitrevskiy ◽  
R. A. Ananyev

In May and October 2017, expeditionary research was carried out in the area of Gelendzhik in the Black Sea at the R/V «Ashamba». The main tasks were the mapping of the seabed and the search for small-sized objects at the bottom of the water area using a WASSP WMB-3250 multibeam echo sounder. Surveys included areal surveying and drawing up bathymetric maps of test sites in Gelendzhik Bay and in the transition zone from the shelf to the continental slope. In addition, the echo sounder was used to search and determine the exact coordinates of the bottom seismograph installed at the seabed near the Divnomorskoye village in May 2016. The article presents the results of the work carried out.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2982 ◽  
Author(s):  
Mun Hua Tan ◽  
Han Ming Gan ◽  
Yin Peng Lee ◽  
Gary C.B. Poore ◽  
Christopher M. Austin

BackgroundWhole mitochondrial DNA is being increasingly utilized for comparative genomic and phylogenetic studies at deep and shallow evolutionary levels for a range of taxonomic groups. Although mitogenome sequences are deposited at an increasing rate into public databases, their taxonomic representation is unequal across major taxonomic groups. In the case of decapod crustaceans, several infraorders, including Axiidea (ghost shrimps, sponge shrimps, and mud lobsters) and Caridea (true shrimps) are still under-represented, limiting comprehensive phylogenetic studies that utilize mitogenomic information.MethodsSequence reads from partial genome scans were generated using the Illumina MiSeq platform and mitogenome sequences were assembled from these low coverage reads. In addition to examining phylogenetic relationships within the three infraorders, Axiidea, Gebiidea, and Caridea, we also investigated the diversity and frequency of codon usage bias and mitogenome gene order rearrangements.ResultsWe present new mitogenome sequences for five shrimp species from Australia that includes two ghost shrimps,Callianassa ceramicaandTrypaea australiensis, along with three caridean shrimps,Macrobrachium bullatum,Alpheus lobidens, andCaridinacf.nilotica. Strong differences in codon usage were discovered among the three infraorders and significant gene order rearrangements were observed. While the gene order rearrangements are congruent with the inferred phylogenetic relationships and consistent with taxonomic classification, they are unevenly distributed within and among the three infraorders.DiscussionOur findings suggest potential for mitogenome rearrangements to be useful phylogenetic markers for decapod crustaceans and at the same time raise important questions concerning the drivers of mitogenome evolution in different decapod crustacean lineages.


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