Structure and diversity of blackfly assemblages in the Luvuvhu River system, South Africa in response to changing environmental gradients

Hydrobiologia ◽  
2021 ◽  
Author(s):  
P. A. Ramulifho ◽  
S. H. Foord ◽  
N. A. Rivers-Moore
Diversity ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 57 ◽  
Author(s):  
Sean N. Porter ◽  
Michael H. Schleyer

Coral communities display spatial patterns. These patterns can manifest along a coastline as well as across the continental shelf due to ecological interactions and environmental gradients. Several abiotic surrogates for environmental variables are hypothesised to structure high-latitude coral communities in South Africa along and across its narrow shelf and were investigated using a correlative approach that considered spatial autocorrelation. Surveys of sessile communities were conducted on 17 reefs and related to depth, distance to high tide, distance to the continental shelf edge and to submarine canyons. All four environmental variables were found to correlate significantly with community composition, even after the effects of space were removed. The environmental variables accounted for 13% of the variation in communities; 77% of this variation was spatially structured. Spatially structured environmental variation unrelated to the environmental variables accounted for 39% of the community variation. The Northern Reef Complex appears to be less affected by oceanic factors and may undergo less temperature variability than the Central and Southern Complexes; the first is mentioned because it had the lowest canyon effect and was furthest from the continental shelf, whilst the latter complexes had the highest canyon effects and were closest to the shelf edge. These characteristics may be responsible for the spatial differences in the coral communities.


2011 ◽  
Vol 46 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Bruce R. Ellender ◽  
Olaf L.F. Weyl ◽  
Ernst R. Swartz

Water SA ◽  
2016 ◽  
Vol 42 (2) ◽  
pp. 183
Author(s):  
Tatenda Dalu ◽  
Taurai Bere ◽  
P William Froneman

2013 ◽  
Vol 89 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Q.M. Dos Santos ◽  
B. Jansen van Vuuren ◽  
A. Avenant-Oldewage

AbstractAn unidentified monogenean diplozoid species was collected from the gills of moggel in the Vaal River and Vaal Dam, South Africa. Specimens were removed from gills of the hosts and observed using light and electron microscopy to compare these diplozoids with known species. The second internal transcribed spacer (ITS2) of the ribosomal gene was amplified, sequenced and compared to that of other diplozoid taxa. Morphological species delimitation was used to determine the identity of these diplozoids, but they did not match the description of any diplozoid taxa. This species is recognized by the specific size of the hooks, number of plicae in posterior and trapezoid anterior projection of the median sclerite connecting to the clamp jaws via a single sclerite, occasionally with two small additional sclerites. Genetic characteristics based on sequence data from the ITS2 region also distinguish this taxon from all other diplozoid taxa. This South African diplozoid grouped in the same clade as Paradiplozoon ichthyoxanthon Avenant-Oldewage, 2013. Data clearly indicate that diplozoids collected from moggel represent a new, distinct taxon of Paradiplozoon Akhmerov, 1974 and are described here as Paradiplozoon vaalense n. sp.


ZooKeys ◽  
2014 ◽  
Vol 453 ◽  
pp. 121-137 ◽  
Author(s):  
Albert Chakona ◽  
Ernst R Swartz ◽  
Paul H. Skelton

2004 ◽  
Vol 24 (4) ◽  
pp. 529-536 ◽  
Author(s):  
A. M. Tsotetsi ◽  
S. N. Mashego ◽  
A. Avenant-Oldewage
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document