Age and growth of Sarpa salpa (Pisces: Sparidae) off the east coast of South Africa

1997 ◽  
Vol 31 (3) ◽  
pp. 241-248 ◽  
Author(s):  
B.A. van der Walt ◽  
L.E. Beckley
Keyword(s):  
South Africa ◽  
East Coast ◽  
Age And Growth ◽  
Sarpa Salpa

Age and growth estimates for the tiger shark, Galeocerdo cuvier, from the east coast of South Africa

2000 ◽  
Vol 51 (1) ◽  
pp. 43 ◽  
Author(s):  
S. P. Wintner ◽  
S. F. J. Dudley
Keyword(s):  
South Africa ◽  
East Coast ◽  
Age And Growth ◽  
Tiger Shark ◽  
Von Bertalanffy ◽  
Growth Rings ◽  
Vertebral Centra ◽  
Galeocerdo Cuvier ◽  
Calculated Length

Growth rings (GR) in sagitally sectioned vertebral centra of 69 female tiger sharks (102–300 cm precaudal length; 6–412 kg) and 32 males (123–301 cm; 16–396 kg) were counted. In vertebrae from three sharks injected with oxytetracyline (OTC) and recaptured after 18, 389 and 791 days of liberty, respectively, OTC was visible and there was evidence of annual GR deposition. Centrum analyses of the entire vertebral sample failed to confirm this GR periodicity. Assuming annual GR deposition, the youngest female and male aged were 1 year (102 cm) and 2 years (123 cm), and the oldest were 11 years (293 cm) and 8 years (301 cm) respectively. von Bertalanffy parameters for the combined sexes based on back-calculated values were L• 301 cm, k 0.202 year−1 and t0 −1.11 years. Ages calculated for length at 50% maturity were 11 years (274 cm) and 8 years (250 cm) for females and males, respectively. Calculated growth in length decreased from 44 cm (0–1 year) to 4 cm (12–13 years). Gompertz parameters were w0 14 kg, G 3.73 and g 0.172 year−1. Calculated growth in mass increased from 12 kg (0–1 year) to 38 kg (7–8 years), then decreased to 29 kg (12–13 years). Back-calculated length and mass values were similar to observed values and Lee’s phenomenon was not evident in either case.

scholarly journals Population irruption of the clam Meretrix morphina in Lake St Lucia, South Africa

2017 ◽  
Vol 113 (7/8) ◽  
Author(s):  
Nelson A. F. Miranda ◽  
Nasreen Peer ◽  
Renzo Perissinotto ◽  
Nicola K. Carrasco ◽  
Salome Jones ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
East Coast ◽  
Severe Drought ◽  
Freshwater Input ◽  
Large Populations ◽  
Ocean Region ◽  
West Indian Ocean ◽  
First Time ◽  
Eastern Seaboard

The thick-shelled clam Meretrix morphina, previously referred to as Meretrix meretrix, now occurs in the west Indian Ocean region, along the eastern seaboard of Africa, from the Red Sea to the Mlalazi Estuary, close to the Tugela River. Its presence in South Africa is only of recent recording. Meretrix morphina was detected for the first time in Lake St Lucia in 2000. The population declined and was not detected from 2005 until 2011, most likely as a result of a severe drought that resulted in widespread desiccation and hypersalinity in the lake. The system then experienced increased freshwater input resulting in lower salinities from 2011 until 2014, during which time M. morphina reappeared and their population gradually increased. In 2015, M. morphina became abundant in St Lucia, attaining unprecedented densities of 447 ind./m2. Biomass, expressed as a fresh weight, varied in the different basins of St Lucia, ranging from 195 g/m2 at Lister’s Point to 1909.8 g/m2 at Catalina Bay. However, in 2016, when drought conditions returned, M. morphina disappeared. This species appears to thrive under brackish salinities and high temperatures. It is able to establish large populations with high biomass and can become dominant. However, M. morphina is sensitive to desiccation and hypersaline conditions. This clam has substantial commercial value and is exploited along the African east coast, particularly in Mozambique. In future, it may feature more prominently in South African estuaries. However, the ecology of M. morphina is still largely unknown.

Possible maternal offloading of metals in the plasma, uterine and capsule fluid of pregnant ragged-tooth sharks (Carcharias taurus) on the east coast of South Africa

2017 ◽  
Vol 24 (20) ◽  
pp. 16798-16805 ◽  
Author(s):  
Kristina Naidoo ◽  
Anil Chuturgoon ◽  
Geremy Cliff ◽  
Sanil Singh ◽  
Megan Ellis ◽  
...  
Keyword(s):  
South Africa ◽  
East Coast ◽  
Carcharias Taurus

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.

Maputo

2020 ◽  
Author(s):  
David Morton
Keyword(s):  
South Africa ◽  
Foreign Investment ◽  
Urban Areas ◽  
East Coast ◽  
18Th Century ◽  
Colonial Rule ◽  
Late 18Th Century ◽  
The Indian Ocean ◽  
Indian Ocean World ◽  
The City

Maputo (Lourenço Marques until 1976) is the capital of Mozambique and one of the busiest port cities on the east coast of Africa. The Bay of Lourenço Marques had already been a source of ivory for the Indian Ocean world and Europe for centuries when, in the late 18th century, Portugal established a permanent garrison there, among the Mpfumo and other Xi-ronga-speaking clans. From 1898 until independence in 1975, the fort-turned-city was the administrative headquarters of Portugal’s territory of Mozambique, a home to many Portuguese settlers, and a stark example of racialized exploitation and urban segregation under colonial rule. It was also the principal transit hub for hundreds of thousands of southern Mozambican men recruited to labor in neighboring South Africa. Following independence, the city became a laboratory of revolutionary socialist experimentation as well as an overcrowded safe haven for refugees of Mozambique’s long and terrible civil war. Despite closer historical ties to South Africa than to most of Mozambique, Maputo is the country’s economic center and its gateway for foreign investment. According to 2017 census figures, the metropolitan population exceeded 2.5 million, making it one of the larger urban areas in southern Africa.

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