scholarly journals Genomic divergence and differential gene expression between crustacean ecotypes across a marine thermal gradient

2020 ◽  
Author(s):  
Arsalan Emami-Khoyi ◽  
Ingrid S. Knapp ◽  
Daniela M. Monsanto ◽  
Bettine Jansen van Vuuren ◽  
Robert J. Toonen ◽  
...  
Keyword(s):  
Gene Expression ◽  
West Coast ◽  
Environmental Gradients ◽  
Expression Profiles ◽  
Molecular Dating ◽  
South Coast ◽  
Decapod Crustaceans ◽  
The West ◽  
Widespread Species ◽  
Genomic Divergence

AbstractEnvironmental gradients between marine biogeographical provinces separate distinct faunal communities; in the absence of absolute dispersal barriers numerous species nonetheless occur on either side of such boundaries. While the regional populations of such widespread species tend to be morphologically indistinguishable from each other, genetic evidence suggests that they represent unique ecotypes, and likely even cryptic species, that may be uniquely adapted to their local environment. Here, we explored genomic divergence in four sympatric southern African decapod crustaceans whose ranges span the boundary between the cool-temperate west coast (south-eastern Atlantic) and the warm-temperate south coast (south-western Indian Ocean) near the southern tip of the African continent. Using genome-wide data, we found that all four species comprise distinct west- and south coast ecotypes, with molecular dating suggesting divergence during the Pleistocene. Using transcriptomic data from one of the decapod crustaceans, we further found a clear difference in gene expression profiles between the west- and south coast ecotypes. This was particularly clear in the individual from the south coast, which experienced a ‘transcriptomic shock’ at low temperatures that are more typical of the west coast and may explain their absence from that coastline. Our results shed new light on the processes involved in driving genomic divergence and incipient speciation.

scholarly journals Has the fishery contributed to a major shift in the distribution of South African sardine?

2008 ◽  
Vol 65 (9) ◽  
pp. 1676-1688 ◽  
Author(s):  
Janet C. Coetzee ◽  
Carl D. van der Lingen ◽  
Laurence Hutchings ◽  
Tracey P. Fairweather
Keyword(s):  
South African ◽  
West Coast ◽  
Management Practices ◽  
Fishing Effort ◽  
South Coast ◽  
The West ◽  
Natal Homing ◽  
Distinct Unit ◽  
Major Shift ◽  
Sardine Population

Abstract Coetzee, J. C., van der Lingen, C. D., Hutchings, L., and Fairweather, T. P. 2008. Has the fishery contributed to a major shift in the distribution of South African sardine? – ICES Journal of Marine Science, 65: 1676–1688. A major shift in the distribution of South African sardine (Sardinops sagax) has resulted in a significant spatial mismatch in fishing effort vs. fish abundance in recent years. The sardine fishery started on the west coast during the 1940s, and processing capacity there increased rapidly. This trend together with increases in annual landings continued up to the early 1960s, but then the fishery collapsed as a consequence of overfishing. The population then recovered steadily during the 1980s and 1990s, coincident with, but perhaps not entirely attributable to, the inception of conservative management practices, to support catches similar to pre-collapse levels. Since 2001, however, most of the sardine population has been situated on South Africa’s south coast, far from processing facilities. Fishing effort has increased concomitantly on that coast, particularly during the past three years, reflecting the continued decline in the abundance of sardine on the west coast. Three hypotheses explaining the change in the distribution of sardine have been proposed: (i) intensely localized (i.e. west coast) fishing pressure depleted that part (or functionally distinct unit) of the population; (ii) the shift was environmentally induced; and (iii) successful spawning and recruit survival on the south coast contributed disproportionately more towards the bulk of recruitment, and progeny spawned there now dominate the population and exhibit natal homing. The first of these hypotheses is evaluated, and management implications of the shift discussed.

Geographic range in Chthamalus along the west coast of North America

2005 ◽  
Vol 85 (2) ◽  
pp. 327-331 ◽  
Author(s):  
J.P. Wares ◽  
A.E. Castañeda
Keyword(s):  
North America ◽  
Cryptic Species ◽  
Genetic Markers ◽  
West Coast ◽  
Environmental Gradients ◽  
Geographic Range ◽  
The West ◽  
Barnacle Species ◽  
Range Overlap

Identification of the range boundaries and microgeographic distribution of cryptic species is greatly facilitated by the use of genetic markers. Here we characterize the geographic range overlap between two cryptic species, Chthamalus fissus and C. dalli, and show that as with other barnacle species, their distribution and abundance is probably dictated more by microhabitat characteristics and the presence of conspecifics than broader environmental gradients. We also show that C. dalli appears to be panmictic across the studied range.

Relative abundances and size compositions of champagne crabs, Hypothalassia acerba, on two coasts and in different water depths and seasons

2004 ◽  
Vol 55 (7) ◽  
pp. 653 ◽  
Author(s):  
Kim D. Smith ◽  
Norman G. Hall ◽  
Ian C. Potter
Keyword(s):  
West Coast ◽  
Carapace Length ◽  
South Coast ◽  
The South ◽  
The West ◽  
Spatial Partitioning ◽  
Invertebrate Predators ◽  
The Mean ◽  
The Difference ◽  
Catch Rates

Hypothalassia acerba was sampled seasonally using traps at depths of 35, 90, 145, 200, 255, 310 and 365 m on the west and south coasts of Western Australia. Catch rates peaked at depths of 200 m on the west coast and 145 m on the south coast but at similar temperatures of 16.1–17.1°C. The west and south coast catches contained 69% and 84% males respectively. The carapace length of H. acerba declined significantly by 4 mm for each 100 m increase in depth. The maximum carapace length of males was greater than females on the west coast (135 v. 113 mm) and south coast (138 v. 120 mm). Furthermore, after adjustment to a depth of 200 m, the mean carapace lengths of males were greater than females on both the west coast (96.6 v. 94.6 mm) and south coast (101.5 v. 91.4 mm), with the difference on the south coast being significant (P < 0.001). Thus, in summary, (1) distribution was related to depth and temperature; (2) body size was inversely related to water depth; and (3) males grew larger and were caught in greater numbers than females. There was also evidence that the distribution changed slightly with season and of spatial partitioning by H. acerba and other large deep-water invertebrate predators.

Bass populations and movements on the west coast of the U.K.

1979 ◽  
Vol 59 (4) ◽  
pp. 889-936 ◽  
Author(s):  
Donovan Kelley
Keyword(s):  
West Coast ◽  
Seasonal Migration ◽  
South Coast ◽  
The South ◽  
The West ◽  
Systematic Pattern ◽  
Discrete Populations

A bass tagging project on the south coast of Anglesey, 1971–5, yielded 86 recoveries from 912 taggings. In addition to expected local movements a systematic pattern of seasonal migration was identified for adults. Fish present in summer moved to south Cornwall for the winter, returning in succeeding summers for spawning. Departure was normally before mid-October. Fish present after that had summered further north (reaching Furness in warm summers). These too moved south as winter advanced, though possibly not reaching Cornwall. A few solitary fish – unfit specimens or members of weak year-classes – appeared to remain through the winter. No evidence was found of movement to, or intermingling with stocks of, the Irish coast; nor, with one exception, the mainland coast of Europe. There was also no indication of movement eastward along the south coast: suggesting discrete populations there from those on the west coast.

Validation of Astropecten jarli Madsen, 1950 and implications for A. cingulatus Sladen, 1883 (Paxillosida: Astropectinidae)

Zootaxa ◽  
2017 ◽  
Vol 4269 (1) ◽  
pp. 101 ◽  
Author(s):  
JOHN M. LAWRENCE ◽  
JANESSA COBB
Keyword(s):  
West Coast ◽  
Valid Species ◽  
The West ◽  
Atlantic Region ◽  
Western Atlantic ◽  
Widespread Species

Astropecten is a major paxillosid genus with a widely occurring presence in tropical and temperate seas. Astropecten jarli from off the west coast of Africa, in the Eastern Atlantic Region, was placed in synonymy with Astropecten cingulatus, a widespread species from the Western Atlantic Region, producing the only amphi-Atlantic Astropecten species. Examination of the holotypes of both species and other specimens of A. cingulatus and A. jarli revealed that A. jarli has a greater major radius:minor radius than A. cingulatus at all sizes, a unique adambulacral spine configuration, and different spination on the inferomarginal plates. ANCOVA indicates A. cingulatus and A. jarli have similar major radius:number of superomarginal plates at small sizes but are distinguishable by the number of superomarginal plates in large individuals. The ratio of the width of the paxillar area:width of the superomarginal plates is greater in A. jarli. Some specimens identified as A. cingulatus from the Eastern Atlantic Region do not fit the description of either A. cingulatus or A. jarli. We conclude that A. jarli is morphologically distinct from A. cingulatus and should be recognized as a valid species. Astropecten cingulatus does not have an amphi-Atlantic distribution and is limited to the Western Atlantic Region.

An aerial survey for sperm whales off the coast of Western Australia 1963-1965.

1968 ◽  
Vol 19 (1) ◽  
pp. 31 ◽  
Author(s):  
JL Bannister
Keyword(s):  
Continental Slope ◽  
Western Australia ◽  
West Coast ◽  
Aerial Survey ◽  
South Coast ◽  
Sperm Whales ◽  
The South ◽  
The West ◽  
Offshore Area ◽  
Direction Of Movement

Objectives, methods, and results of a two-year aerial survey for sperm whales off the coast of Western Australia, 1963-65, are described. Data from commercial whaling operations have been included where appropriate. Sperm whales were found well off the west coast, but only in a narrow strip along the continental slope off the south coast. On both coasts, the main direction of movement was parallel to the coastline and towards Cape Leeuwin. Unexpectedly, whales off the west coast were heading mainly southwards throughout the year. Densities in the offshore area north of Perth were significantly higher than along the continental slope in the same region but similar to those along the continental slope from Perth to Cape Leeuwin. The situation was reversed on the south coast with whales being found, in high densities, only along the continental slope. Off the west coast, there were marked decreases in abundance in winter, with peaks in spring-early summer and autumn; no change in direction of movement could be related to the peaks. Average numbers calculated as present in the survey area at one time were: west coast, c. 1000 whales; south coast, c. 200 whales. South coast data indicate the passage of about 40 whales in one 24 hr period, very similar to results from whaling company aerial spotter data off Albany. The hypothesis of two separate populations of sperm whales off Western Australia is discussed and thought to be unlikely. A small amount of data on baleen whale sightings is recorded.

scholarly journals Emerita pangandaranensis sp. nov., a new sand crab (Anomura: Hippidae) from South Coast of Java, Indonesia

2021 ◽  
Author(s):  
Nisfa Hanim ◽  
Achmad Farajallah ◽  
Vinna Putri
Keyword(s):  
New Species ◽  
West Coast ◽  
Sandy Beaches ◽  
The Other ◽  
South Coast ◽  
Intertidal Area ◽  
The West ◽  
West Java ◽  
Preferred Habitat ◽  
The World

The report of genus Emerita from Indonesia has only contained one species, namely Emerita emeritus. They were found on the west coast of Sumatera and the south coast of Java. Although Indonesia is the number two country in the world that has long beaches and is dominated by sandy beaches, as the preferred habitat for sand crabs, reports regarding these biotas in Indonesia are still limited. The previous studies have expected about the occurrence of the other species which was related to Emerita emeritus in Southern Java. We reported the new species of Emerita which was found in Pangandaran beach, West Java. We found it in an intertidal area, near Citonjong Estuary. Here, we described and illustrated the species.

scholarly journals Preliminary account of the mapping of the Mesozoic formations of south-east Jameson Land

1971 ◽  
Vol 37 ◽  
pp. 24-32
Author(s):  
F Surlyk ◽  
R.G Bromley ◽  
U Asgaard ◽  
K.R Pedersen
Keyword(s):  
West Coast ◽  
South Coast ◽  
Special Study ◽  
Topographic Map ◽  
The West ◽  
Full Report ◽  
Preliminary Account ◽  
Field Season ◽  
Geological Map ◽  
Special Studies

In the 1970 field season, the programme of mapping Jameson Land (Birkelund & Perch-Nielsen, 1969; Bromley et al., 1970) was continued with·a study of the Hurry Fjord region and the area between Mønselv and Raukelv on the south coast (fig. 6). The geology of the west coast of Hurry Fjord has been studied previously by Hartz (1896), Harris (1926, 1937), Rosenkrantz (1934) and Aldinger (1935), and certain parts of the succession are known in detail. During the 1970 field season, however, special study was made of the phytopalaeontology of the Kap Stewart Formation (K.R.P.), the ichnology of the Neill Klinter Formation (R.G.B. & U.A.) and the stratigraphy of the Kap Biot Formation and the beds overlying the Neill Klinter Formation (F.S.). These special studies will be published later. A full report of the mapping must wait until a more detailed topographic map is available for the publication of the geological map.

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