Intertidal population structure of the edible mollusc Turbo sarmaticus (Vetigastropoda) at an unexploited and exploited sites along the coast of the Eastern Cape Province, South Africa
- Foster, Gregory G, Hodgson, Alan N
- Authors: Foster, Gregory G , Hodgson, Alan N
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447403 , vital:74622 , https://doi.org/10.1080/15627020.2000.11657088
- Description: The intertidal population structure of the large edible gastropod Turbo sarmaticus was examined at four sites along the Eastern Cape Province of South Africa. One site was free from exploitation, two were subjected to low levels of exploitationand one was heavily exploited. Within the intertidal zone at all sites there was a size-related distribution, with smalleranimals being found towards the upper mid-shore and larger animals occurring in a downshore direction. The mean shore densities (1.2–animals/m2) and biomass (4.4–9.4 g/m2) of T. sarmaticus at the sites where there was no, or minimal, exploitation of animals were not significantly different (P0.001). However, the largest animals (up to 110mmshell length) were found at the unexploited site, an offshore island. The lowest density (0.2 animals/m2) and biomass (0.4 g/m2) of T. sarmaticus was recorded at the site where the exploitation of this gastropod was intense. In addition, no animals of a legally exploitable size (>70 mm shell length) were found. It is suggested that intense over-exploitation is threatening the population at this site.
- Full Text:
- Date Issued: 2000
- Authors: Foster, Gregory G , Hodgson, Alan N
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447403 , vital:74622 , https://doi.org/10.1080/15627020.2000.11657088
- Description: The intertidal population structure of the large edible gastropod Turbo sarmaticus was examined at four sites along the Eastern Cape Province of South Africa. One site was free from exploitation, two were subjected to low levels of exploitationand one was heavily exploited. Within the intertidal zone at all sites there was a size-related distribution, with smalleranimals being found towards the upper mid-shore and larger animals occurring in a downshore direction. The mean shore densities (1.2–animals/m2) and biomass (4.4–9.4 g/m2) of T. sarmaticus at the sites where there was no, or minimal, exploitation of animals were not significantly different (P0.001). However, the largest animals (up to 110mmshell length) were found at the unexploited site, an offshore island. The lowest density (0.2 animals/m2) and biomass (0.4 g/m2) of T. sarmaticus was recorded at the site where the exploitation of this gastropod was intense. In addition, no animals of a legally exploitable size (>70 mm shell length) were found. It is suggested that intense over-exploitation is threatening the population at this site.
- Full Text:
- Date Issued: 2000
Feeding, tentacle and gut morphology in five species of southern African intertidal holothuroids (Echinodermata)
- Foster, Gregory G, Hodgson, Alan N
- Authors: Foster, Gregory G , Hodgson, Alan N
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447392 , vital:74621 , https://hdl.handle.net/10520/AJA00445096_757
- Description: Compares the structure of the tentacles and digestive tracts of four species of intertidal dendrochirote, and one species of aspidochirote holothuroid by using light, scanning and transmission electron microscopy. Gut contents were sieved to determine the size of the particulate matter ingested. Concludes that there appears to be a relationship between tentacle morphology and the size and type of food ingested. Gut length, the thickness of the digestive epithelial layer and the number of vesicles present in the enterocyte cells of the digestive epithelium also differ in relation to the food ingested. Illustrates with several photographs.
- Full Text:
- Date Issued: 1996
- Authors: Foster, Gregory G , Hodgson, Alan N
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447392 , vital:74621 , https://hdl.handle.net/10520/AJA00445096_757
- Description: Compares the structure of the tentacles and digestive tracts of four species of intertidal dendrochirote, and one species of aspidochirote holothuroid by using light, scanning and transmission electron microscopy. Gut contents were sieved to determine the size of the particulate matter ingested. Concludes that there appears to be a relationship between tentacle morphology and the size and type of food ingested. Gut length, the thickness of the digestive epithelial layer and the number of vesicles present in the enterocyte cells of the digestive epithelium also differ in relation to the food ingested. Illustrates with several photographs.
- Full Text:
- Date Issued: 1996
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