scholarly journals The marine algae of Hluleka (Transkei) and the warm temperate/sub-tropical transition on the east coast of southern Africa

1987 ◽  
Vol 41 (2) ◽  
pp. 165-183 ◽  
Author(s):  
J. J. Bolton ◽  
H. Stegenga
Keyword(s):  
Southern Africa ◽  
Marine Algae ◽  
East Coast ◽  
Warm Temperate

Taxonomic Review of the perciform fish genus Acanthistius from the east coast of southern Africa, with description of a new species and designation of a neotype for Serranus sebastoides Castelnau, 1861

Zootaxa ◽  
2010 ◽  
Vol 2352 (1) ◽  
pp. 59 ◽  
Author(s):  
PHILLIP C. HEEMSTRA
Keyword(s):  
South Africa ◽  
New Species ◽  
South America ◽  
Southern Africa ◽  
East Coast ◽  
Valid Species ◽  
Shallow Waters ◽  
Single Specimen ◽  
Warm Temperate ◽  
A New Species

The genus Acanthistius Gill, 1862 comprises ten putative valid species occurring in shallow warm-temperate waters of the Southern Hemisphere: South America (coasts of Ecuador, Peru, Chile, Brazil, and Argentina) southern Africa (Namibia and South Africa), southern Australia, New Zealand, Lord Howe, Norfolk, Kermadec and Easter, and Sala y Gómez islands. Two species: Acanthistius sebastoides (Castelnau, 1861) and Acanthistius sp are known from shallow waters of the east coast of South Africa (Heemstra and Randall, 1986). The latter taxon, previously known from a brief description of a single specimen, is here described from 23 specimens and named Acanthistius joanae. Acanthistius sebastoides is redescribed from 13 specimens and compared with A. joanae and species of Acanthistius known from South America and Australia. A neotype is designated for Serranus sebastoides Castelnau, 1861, as the two syntypes are apparently lost.

scholarly journals Marine Heatwaves Exceed Cardiac Thermal Limits of Adult Sparid Fish (Diplodus capensis, Smith 1884)

2021 ◽  
Vol 8 ◽  
Author(s):  
Kerry-Ann van der Walt ◽  
Warren M. Potts ◽  
Francesca Porri ◽  
Alexander C. Winkler ◽  
Murray I. Duncan ◽  
...  
Keyword(s):  
Heart Rate ◽  
East Coast ◽  
Reaction Rates ◽  
Range Limit ◽  
Thermal Indices ◽  
Thermal Thresholds ◽  
Thermal Limits ◽  
Relative Change ◽  
Warm Temperate ◽  
Established Technique

Climate change not only drives increases in global mean ocean temperatures, but also in the intensity and duration of marine heatwaves (MHWs), with potentially deleterious effects on local fishes. A first step to assess the vulnerability of fishes to MHWs is to quantify their upper thermal thresholds and contrast these limits against current and future ocean temperatures during such heating events. Heart failure is considered a primary mechanism governing the upper thermal limits of fishes and begins to occur at temperatures where heart rate fails to keep pace with thermal dependency of reaction rates. This point is identified by estimating the Arrhenius breakpoint temperature (TAB), which is the temperature where maximum heart rate (fHmax) first deviates from its exponential increase with temperature and the incremental Q10 breakpoint temperature (TQB), which is where the Q10 temperature coefficient (relative change in heart rate for a 10°C increase in temperature) for fHmax abruptly decreases during acute warming. Here we determined TAB, TQB and the temperature that causes cardiac arrhythmia (TARR) in adults of the marine sparid, Diplodus capensis, using an established technique. Using these thermal indices results, we further estimated adult D. capensis vulnerability to contemporary MHWs and increases in ocean temperatures along the warm-temperate south-east coast of South Africa. For the established technique, we stimulated fHmax with atropine and isoproterenol and used internal heart rate loggers to measure fHmax under conditions of acute warming in the laboratory. We estimated average TAB, TQB, and TARR values of 20.8°C, 21.0°C, and 28.3°C. These findings indicate that the physiology of D. capensis will be progressively compromised when temperatures exceed 21.0°C up to a thermal end-point of 28.3°C. Recent MHWs along the warm-temperate south-east coast, furthermore, are already occurring within the TARR threshold (26.6–30.0°C) for cardiac function in adult D. capensis, suggesting that this species may already be physiologically compromised by MHWs. Predicted increases in mean ocean temperatures of a conservative 2.0°C, may further result in adult D. capensis experiencing more frequent MHWs as well as a contraction of the northern range limit of this species as mean summer temperatures exceed the average TARR of 28.3°C.

East Coast Fever

2021 ◽  
pp. 195-220
Author(s):  
Sammy Gichuhi Ndungu ◽  
Sebastian K. Waruri ◽  
James M. Wanjohi
Keyword(s):  
Southern Africa ◽  
East Coast ◽  
Protozoan Parasite ◽  
Rhipicephalus Appendiculatus ◽  
East Coast Fever ◽  
Therapeutic Drugs ◽  
Major Constraint ◽  
Drug Companies ◽  
Ear Tick ◽  
The Cost

East coast fever, a disease of cattle caused by the protozoan parasite Theileria parva and transmitted by the three-host tick Rhipicephalus appendiculatus (the brown ear tick), is a major constraint to cattle production in Eastern, Central, and Southern Africa. In Kenya it is the most important tick-borne disease and a major constraint in cattle productivity. This is due to the high morbidity and mortality it causes in susceptible herds, the cost of control of the vector ticks, and the cost of treatment of clinical cases. Animals that recover from the disease also suffer from reduced productivity which can be long term. The limited distribution of the tick and the disease to only East, Central and Southern Africa also means that the market for therapeutic drugs and acaricides is small. Therefore, drug companies are not keen on funding research and development of new drug and acaricide molecules when resistance occurs.

Cyclacanthia n.g. (Demospongiae: Poecilosclerida: Latrunculiidae incertea sedis), a new genus of marine sponges from South African waters, and description of two new species

Zootaxa ◽  
2004 ◽  
Vol 725 (1) ◽  
pp. 1 ◽  
Author(s):  
TOUFIEK SAMAAI ◽  
VASHA GOVENDER ◽  
MICHELLE KELLY
Keyword(s):  
South African ◽  
Type Species ◽  
New Genus ◽  
East Coast ◽  
Hot Spot ◽  
Marine Sponges ◽  
The Family ◽  
Two New Species ◽  
Shallow Subtidal ◽  
Warm Temperate

The new genus Cyclacanthia n.g. is erected in the poecilosclerid Family Latrunculiidae for the type species Latrunculia bellae Samaai & Kelly, 2003, and two further species, Cyclacanthia cloverlyae sp. nov., and Cyclacanthia mzimayiensis sp. nov.. The latter species are from the subtropical east coast of South Africa, whereas C. bellae has only been found further south in warm temperate Algoa Bay. Cyclacanthia n.g. differs from other Latrunculiidae genera in the ontogeny, morphology and structure of the mature microsclere, the isospinodiscorhabd, which has only three major whorls of projections as opposed to the four in species of Latrunculia du Bocage. Additional diagnostic characters include the presence of broad swathes of megascleres that diverge from the base of the sponge towards the upper choanosome, where they form loose brushes and the typical whispy reticulation of most Latrunculiidae. The ectosome is composed of a dense tangential layer of megascleres, an irregular palisade of microscleres at the surface, and a permanently encrusting habit. Cyclacanthia n.g. is the second new latrunculid genus recently described from shallow subtidal South African waters, following major revision of the family. The presence of species in four of the five known genera in the family, on South African coastlines, suggests a diversity hot-spot for the family in this region.

Marine mammals and Japanese long-line fishing vessels in Australian waters: operational interactions and sightings

2006 ◽  
Vol 12 (1) ◽  
pp. 31 ◽  
Author(s):  
Catherine Bell ◽  
Peter Shaughnessy ◽  
Margie Morrice ◽  
Bob Stanley
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
East Coast ◽  
Fishing Gear ◽  
Killer Whales ◽  
Fishing Vessels ◽  
Long Line ◽  
Target Fish ◽  
Pilot Whales ◽  
Warm Temperate

Observers from the Australian Fisheries Management Authority worked on randomly chosen Japanese long-line vessels in the Australian Fishing Zone (AFZ) between 1980 and 1997. Observer reports (n = 451) were inspected for interactions or sightings of marine mammals. An operational interaction was defined as an activity or behaviour that involved direct contact between a marine mammal and fishing gear, bait, target fish or bycatch, or indications that the marine mammal was feeding. A sighting was defined as the recording of marine mammals that passed the vessel without changing course and/or did not appear to interact with the vessel or its gear. Observers witnessed 23 interactions and made another 44 sightings of marine mammals. A further 24 interactions and sightings were relayed by crew members. Killer whales were reported most frequently: most incidences of fish being damaged, taken or frightened away were attributed to them. Eleven marine mammals were caught: two died, seven were released, and the fate of two others was not recorded. Between 1991 and 1996, when observer coverage was 11.5% overall in the AFZ, the incidence of interactions was 1.71 per million hooks set. The estimated number of interactions in that seven-year period was 157 in the AFZ. Since 1997, the long-line fishery has been conducted by Australian vessels, primarily off the east coast of mainland Australia in warm-temperate waters. A higher proportion of interactions can be expected with killer whales and short-finned pilot whales in these waters, and fewer with seals.

scholarly journals A preliminary fish survey of the estuaries on the south-east coast of South Africa, Kei Estuary to Mdumbi: A comparative study

Water SA ◽  
2020 ◽  
Vol 46 (3 July) ◽  
Author(s):  
NC James ◽  
TD Harrison
Keyword(s):  
South Africa ◽  
Significant Relationship ◽  
East Coast ◽  
Multivariate Analyses ◽  
Fish Communities ◽  
Chemical Characteristics ◽  
The South ◽  
Physico Chemical ◽  
Biogeographic Region ◽  
Warm Temperate

A preliminary ichthyofaunal and physico-chemical survey of estuaries on the south-east coast of South Africa from the Kei Estuary to the Mdumbi Estuary was undertaken between October and November 1997. Twenty-seven (27) estuaries were surveyed along this stretch of coastline and these were grouped into three estuary types: small (< 10 ha) predominantly closed estuaries, moderate to large (> 10 ha) predominantly closed estuaries and predominantly open estuaries. Multivariate analyses revealed significant differences between predominantly closed estuaries and predominantly open estuaries in terms of both their physico-chemical characteristics and their fish communities. There was no difference between small and moderate to large predominantly closed estuaries.  A significant relationship was also observed between the physico-chemical characteristics of the estuaries and their fish communities.  The estuaries in the study area fall within the warm-temperate biogeographic region; temperate species dominated the fish communities of all the estuaries. This survey represents one of the few fish surveys undertaken along this little-studied section of the coastline. 

scholarly journals Analysis of p67 allelic sequences reveals a subtype of allele type 1 unique to buffalo-derived Theileria parva parasites from southern Africa

2020 ◽  
Author(s):  
Lubembe D. Mukolwe ◽  
David O. Odongo ◽  
Charles Byaruhanga ◽  
Louwtjie P. Snyman ◽  
Kgomotso P. Sibeko-Matjila
Keyword(s):  
South Africa ◽  
East Africa ◽  
Southern Africa ◽  
East Coast ◽  
East Coast Fever ◽  
African Countries ◽  
Gene Encoding ◽  
Allele Type

AbstractEast Coast fever (ECF) and Corridor disease (CD) caused by cattle- and buffalo-derived T. parva respectively are the most economically important tick-borne diseases of cattle in the affected African countries. The p67 gene has been evaluated as a recombinant subunit vaccine against East Coast fever (ECF), and for discrimination of T. parva parasites causing ECF and Corridor disease (CD). The p67 allele type 1 was first identified in cattle-derived T. parva parasites from east Africa, where parasites possessing this allele type have been associated with ECF. Subsequent characterization of buffalo-derived T. parva parasites from South Africa where ECF was eradicated, revealed the presence of a similar allele type, raising concerns as to whether or not allele type 1 from parasites from the two regions is identical. A 900 bp central fragment of the gene encoding p67 was PCR amplified from T. parva DNA extracted from blood collected from cattle and buffalo in South Africa, Mozambique, Kenya, Tanzania and Uganda, followed by DNA sequence analysis. Four p67 allele types previously described were identified. A subtype of p67 allele type 1 was identified in parasites from clinical cases of CD and buffalo from southern Africa. Notably, p67 allele type 1 sequences from parasites associated with ECF in East Africa and CD in Kenya were identical. Analysis of two p67 B-cell epitopes (TpM12 and AR22.7) revealed amino acid substitutions in allele type 1 from buffalo-derived T. parva parasites from southern Africa. However, both epitopes were conserved in allele type 1 from cattle- and buffalo-derived T. parva parasites from East Africa. These findings reveal detection of a subtype of p67 allele type 1 associated with T. parva parasites transmissible from buffalo to cattle in southern Africa.

scholarly journals The historical development of physical research on the oceans bordering Southern Africa

1982 ◽  
Vol 1 (1) ◽  
pp. 42-52 ◽  
Author(s):  
J. R. E. Lutjeharms
Keyword(s):  
Ocean Circulation ◽  
Southern Africa ◽  
East Coast ◽  
Phenomenological Research ◽  
Historical Research ◽  
Western Boundary ◽  
Boundary Current ◽  
The West ◽  
Publication Rates ◽  
Circulation Patterns

Two archetypal ocean circulation patterns occur in the oceanic areas adjacent to southern Africa, namely, a western boundary current on the east coast and upwelling on the west coast. Investigation on the physical behaviour of these systems has passed through phases of exploratory, descriptive and phenomenological research. These historical research patterns are described briefly using mostly the publication rates on the physical oceanology of the areas in question.

scholarly journals Residency Patterns and Migration Dynamics of Adult Bull Sharks (Carcharhinus leucas) on the East Coast of Southern Africa

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e109357 ◽  
Author(s):  
Ryan Daly ◽  
Malcolm J. Smale ◽  
Paul D. Cowley ◽  
Pierre W. Froneman
Keyword(s):  
Southern Africa ◽  
East Coast ◽  
Carcharhinus Leucas ◽  
Migration Dynamics ◽  
And Migration
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