http://hdl.handle.net/10386/74 2026-04-05T16:14:20Z 2026-04-05T16:14:20Z Madiseng, Mogaletloa Eugene http://hdl.handle.net/10386/4954 2025-03-29T01:00:19Z 2024-01-01T00:00:00Z

Evolution of acoustic communication and habitat type influence in the avian species, sabota lark calendulauda sabota (alaudidae) Madiseng, Mogaletloa Eugene Habitat acoustics has been proposed to be involved in producing selective forces that mould bird vocalisations into the sounds we hear when birds vocalise. The influence of habitat on bird vocalisations is well-documented, mostly in bird species in the Americas rather than in Africa. The Sabota Lark Calendulauda sabota is near-endemic to southern Africa and has a widespread distribution in habitats ranging from well-developed Savanna woodland to Karoo and semi-desert scrub. However, to my knowledge, no records of published studies have endeavoured to quantitatively describe the vocal structure of the Sabota Lark or the effects of habitat on its vocalisations. This makes the Sabota Lark an ideal candidate to investigate the effect of habitat type and structure on bird vocal structure. This study investigated the effect of habitat on the vocalisations of the Sabota Lark and whether the Acoustic Adaptation Hypothesis applies to the Sabota Lark. Fieldwork was conducted during breeding seasons in the sites that represented semi-arid (Vachellia) and moist Savanna (broad-leaved woodland) and the dry Nama Karoo shrublands. Songs were analysed using a bioacoustics sound analyses software. A total of 992 song strophes were extracted, and spectrograms were generated from which descriptions of songs were done. Seven spectrogram parameters of 878 song strophes were analysed using univariate one-way ANOVA and t-test. Multivariate (Principal Component Analyses – PCA and Linear Discriminant Analyses – LDA) statistical analyses were performed in two parts to respectively include: 1) analyses of a comprehensive dataset with all the remaining seven vegetation types included and 2) analyses of a reduced dataset comprising only the two vegetation types with the highest sampling (viz., Bushmanland Basin Shrubland – BBS and Musina Mopane Bushveld – MMB). The Sabota Lark emerged as a species with large and complex song variations between individual birds and within and between different habitat types. The individuals gave many unique song types and song strophes. Furthermore, this species explored both types of song presentation or singing styles as some individuals repeated song types at least twice before switching to another song type. This singing style is called “eventual variety”. The other birds rendered their song types once and never twice in succession. This is called “immediate” variety, meaning they switched to new song types immediately without repeating songs that have already been sung. This was observed both within individuals and among individuals in different habitat types. The means of the parameters of song strophes of the Sabota Larks among the vegetation types were highly significantly different, indicating that variances in songs between vegetation types were not equal. However, most parameters were significantly different contrary to the study predictions; Therefore, future studies should include a large sample size with equal representation across habitats, and the vegetation structure should be quantified. Thesis (M. Sc. (Zoology)) -- University of Limpopo, 2024

2024-01-01T00:00:00Z Madiseng, Mogaletloa Eugene http://hdl.handle.net/10386/4943 2025-03-25T01:00:24Z 2024-01-01T00:00:00Z

Evolution of acoustic communication and habitat type influence in the avian species, sabota lark calendulauda sabota (alaudidae) Madiseng, Mogaletloa Eugene Habitat acoustics has been proposed to be involved in producing selective forces that mould bird vocalisations into the sounds we hear when birds vocalise. The influence of habitat on bird vocalisations is well-documented, mostly in bird species in the Americas rather than in Africa. The Sabota Lark Calendulauda sabota is near-endemic to southern Africa and has a widespread distribution in habitats ranging from well-developed Savanna woodland to Karoo and semi-desert scrub. However, to my knowledge, no records of published studies have endeavoured to quantitatively describe the vocal structure of the Sabota Lark or the effects of habitat on its vocalisations. This makes the Sabota Lark an ideal candidate to investigate the effect of habitat type and structure on bird vocal structure. This study investigated the effect of habitat on the vocalisations of the Sabota Lark and whether the Acoustic Adaptation Hypothesis applies to the Sabota Lark. Fieldwork was conducted during breeding seasons in the sites that represented semi-arid (Vachellia) and moist Savanna (broad-leaved woodland) and the dry Nama Karoo shrublands. Songs were analysed using a bioacoustics sound analyses software. A total of 992 song strophes were extracted, and spectrograms were generated from which descriptions of songs were done. Seven spectrogram parameters of 878 song strophes were analysed using univariate one-way ANOVA and t-test. Multivariate (Principal Component Analyses – PCA and Linear Discriminant Analyses – LDA) statistical analyses were performed in two parts to respectively include: 1) analyses of a comprehensive dataset with all the remaining seven vegetation types included and 2) analyses of a reduced dataset comprising only the two vegetation types with the highest sampling (viz., Bushmanland Basin Shrubland – BBS and Musina Mopane Bushveld – MMB). The Sabota Lark emerged as a species with large and complex song variations between individual birds and within and between different habitat types. The individuals gave many unique song types and song strophes. Furthermore, this species explored both types of song presentation or singing styles as some individuals repeated song types at least twice before switching to another song type. This singing style is called “eventual variety”. The vi other birds rendered their song types once and never twice in succession. This is called “immediate” variety, meaning they switched to new song types immediately without repeating songs that have already been sung. This was observed both within individuals and among individuals in different habitat types. The means of the parameters of song strophes of the Sabota Larks among the vegetation types were highly significantly different, indicating that variances in songs between vegetation types were not equal. However, most parameters were significantly different contrary to the study predictions; Therefore, future studies should include a large sample size with equal representation across habitats, and the vegetation structure should be quantified Thesis (M. Sc. (Zoology) -- University of Limpopo, 2024

2024-01-01T00:00:00Z Lukhele, Linda Prince http://hdl.handle.net/10386/4879 2025-02-08T01:00:23Z 2024-01-01T00:00:00Z

A study of ichthyoparasites from imported ornamental fish from Indonesia and Sri Lanka and possible host-parasite interactions and Lukhele, Linda Prince The current study aimed to investigate the prevalence, mean intensity and parasite composition from fishes imported from Sri Lanka to determine the effectiveness of Sri Lanka’s treatment strategy against parasite infestations, and to determine the host-parasite interactions between Glossolepis incisus from Indonesia and its associated parasites. The keeping of ornamental fish has become a popular hobby among millions of enthusiasts worldwide, including in South Africa. Most ornamental fish sold on the South African market are alien and imported from countries such as Sri Lanka and Indonesia. Ornamental fish along with their parasites can be introduced into local aquatic systems. The repercussions of introducing alien ichthyoparasites to native species have been documented. However, currently, in South Africa, the legislation does not require that imported fish destined for the pet industry be quarantined or treated against parasites. Sri Lanka has gained a reputation for effectively treating ornamental fish before exporting them to other countries. In this study, 11 ornamental fish species from nine families were imported via WCB Import from Sri Lanka (n = 10) and Indonesia (n = 1) and examined for parasites within 24 hours of their arrival in South Africa. In the laboratory, fish were sacrificed by percussive stunning and cervical transection, dissected, and the organs were placed in Petri dishes and scrutinised for parasites through a compound microscope, whilst skin smears were scrutinised under a stereo microscope. Observed parasites were collected and preserved using standard methods and their prevalence and mean intensity were determined. Of the 10 species received from Sri Lanka and examined, five were found to be infected by parasites. Two groups of parasites were collected from the fishes, these being Branchiura and Monogenea, with monogeneans being the most dominant. Branchiura was represented by a single species, whilst Monogenea was represented by five genera and eight species. A single specimen of branchiuran was collected from C. auratus and identified as Argulus japonicus. Monogeneans collected from C. auratas were Dactylogyrus baueri, Dactylogyrus intermedius, Gyrodactylus gurleyi and Gyrodactylus kobayashii. In turn, Hypostomus plecostomus was infected by the monogenean Heteropriapulus heterotylus with Metynnis hypsauchen, Pangasianodon hypophthalmus and Barbonymus schwanenfeldii each infected by Urocleidoides sinus, Thaparocleidus caecus and Dactylogyrus lampam respectively. Branchiura recorded the lowest prevalence and iv intensity at 6.7% and 1% respectively. The prevalence for monogenean parasites varied between 60% for H. heterotylus from H. plecostomus and 100% for T. caecus from P. hypophthalmus. The mean intensity for monogenean parasites varied between 5.1 for H. heterotylus from H. plecostomus and 224.2 for T. caecus from P. hypophthalmus. In a separate trial, host-parasite interactions using Glossolepis incisus were investigated over nine weeks. Upon arrival at the University of Limpopo, Parasitology Laboratory, 15 specimens were sacrificed and examined for parasites. The next week another 15 specimens were examined. Thereafter, on a biweekly basis, 15 specimens that were housed in aquaria were randomly selected and examined for parasites. The nematode Camallanus cotti and a new monogenean species (Ancryocephalidae n. gen.) were collected from the fish examined. Throughout the trial, no trend in parasite numbers was observed for monogeneans. However, a high ammonia concentration and eutrophication were associated with an increase in monogenean numbers. A decrease in nematode numbers was observed due to these parasites having a lower survival rate under aquarium conditions thought to be due to the absence of the intermediate host. Water changes and reduced fish congestion were also linked to a decrease in both monogenean and nematode numbers. Monogeneans generally share very similar morphological features, and thus their identifications have to be genetically confirmed. Amongst the collected monogenean species in the current study, the 18S, ITS1 and 28S rDNA segments were successfully sequenced for only T. caecus and Ancyrocephalidae n. gen. Two haplotypes of T. caecus were revealed. Therefore, the current study recognises the need to re-evaluate the morphometry of the typematerial of T. caecus, to establish which genotype represents T. caecus and which would be a new species of high morphological similarity to T. caecus. Ancyrocephalidae n. gen. was genetically confirmed to be a new monogenean species. The current study therefore presents the first DNA sequencing of 18S, ITS1 and 28S rDNA segments of monogenean parasites collected from the host species G. incisus. Since some of the fishes examined in this study were observed to be infected with parasites, the risk of their introduction and possibly invasion into local systems still exists. The current study therefore recommends that the South African authorities at customs put in place quarantine and treatment protocols for live fish imported into the country. Thesis (M.Sc. (Zoology)) -- University of Limpopo, 2024

2024-01-01T00:00:00Z Maginya, Thabelo http://hdl.handle.net/10386/4829 2025-01-31T01:00:21Z 2023-01-01T00:00:00Z

Parasite diversity and health of chiloglanis pretoriae and amphilius uranoscopus from the Limpopo River System Maginya, Thabelo The African continent has rich freshwater fish fauna, but the parasite composition of only a few species is known. Chiloglanis pretoriae Van der Horst, 1931 and Amphilius uranoscopus (Pfeffer, 1889) are among African freshwater fish endemic to South Africa with limited information about their parasite composition and health status. A total of 171 fishes, C. pretoriae (n = 127) and A. uranoscopus (n = 44) from Nwanedi, Mutshundudi, Lutanandwa and Politsi rivers within the Limpopo River System, were collected to determine their parasite diversity and health. Both ecto- and endoparasites were recovered and preserved for identification. Scanning electron microscopy and morphological, morphometric and molecular analysis were used for parasite identification. Parasite infestation indices for all parasites were calculated and compared among the four rivers. The water quality of the rivers was investigated by measuring the selected physico-chemical parameters. Subsurface water samples were collected for analysis of selected metals and nutrients. The Health Assessment Index (HAI) in conjunction with the Inverted Parasite Index (IPI), condition factor (K) and regression analysis were calculated to determine the health of fish. Species richness and parasite diversity of C. pretoriae and A. uranoscopus from the four rivers were calculated using Margalef’s richness index and Shannon-Weiner diversity index, respectively. Parasite diversity and species richness of C pretoriae and A. uranoscopus were compared to the water quality of the four localities. Three parasitic groups (Monogenea, Digenea and Hirudinea) were found from C. pretoriae which comprised of two ectoparasite species [Dactylogyridae gen. sp. (n = 56) and a leech (n = 4)] and three endoparasite species [Clinostomum sp. (n = 4), Diplostomidae gen. sp. larva (n = 143) and Cephalogonimidae gen. sp. (n = 19)]. Ectoparasites were more abundant in the Lutanandwa River with a total of 54, while endoparasites were more abundant in the Mutshundudi River with a total of 106. Diplostomidae gen. sp. from C. pretoriae in the Mutshundudi River had the highest prevalence of 57.14%, and the leech from the Nwanedi River had the lowest prevalence of 0.25%. Chiloglanis pretoriae from Nwanedi River had the highest Shannon-Weiner and Margalef’s index values of 0.53 and 0.54, respectively, indicating a healthy ecosystem. Two endoparasite groups, digeneans (Clinostomum sp., Uvulifer sp. and Cephalogonimidae gen. sp.) and nematodes (Labeonema sp., Contracaecum sp., Rhabdochona sp., Gendria sp. and Gendria cf. paski) were found in A. uranoscopus. v Uvulifer sp. was the most prevalent parasite with a 100% prevalence. Amphilius uranoscopus from Lutanandwa River had the highest Shannon-Weiner Index and Margalef’s index values of 0.26 and 0.30, respectively, and a low evenness value of 0.37 due to uneven distribution of parasite species. The highest HAI value for C. pretoriae (36.19) was recorded from the Mutshundudi River and the lowest of 28.38 was recorded from the Lutanandwa River. The highest K score for C. pretoriae of 1.08 was recorded from Nwanedi River and the lowest of 1.01 from Lutanandwa River. The HAI of A. uranoscopus from the four selected localities indicated that the fish collected from the Lutanandwa River were in poorer health state than those from the other rivers due to the higher score. The highest HAI of 99.13 was recorded from the Lutanandwa River and the lowest HAI of 36.36 was recorded from the Nwanedi River. However, the highest mean K score of 0.84 was recorded from Nwanedi River while the lowest of 0.53 was recorded from Mutshundudi River. The results of both C. pretoriae and A. uranoscopus also indicated that the parasite burden did not affect the K of the fish. Generally, water quality results indicated that the rivers were in fair condition with most parameters being within the acceptable target water quality range (TWQR) of aquatic ecosystems. These rivers therefore have good water quality and indicate an oligotrophic state, however, Nwanedi and Politsi rivers are slightly impacted by anthropogenic factors which increased their nitrate concentration compared to the other rivers (Mutshundudi and Lutanandwa rivers). During this study, fish health, parasite diversity and species richness indices were used in combination to determine the water quality of the four localities. The results represent new geographical and host records for parasites from C. pretoriae and A. uranoscopus in the Nwanedi, Mutshundudi, Lutanandwa and Politsi rivers. Since it is the first record of Cephalogonimidae gen. sp. and Dactylogyridae gen. sp., more studies should be done to investigate other possible localities within the Limpopo River System and determine the life cycle of the digenean. Since both parasites represent new genera, papers on their description and identification are in preparation. Future studies on the parasites of the two fish species should employ the use of molecular analysis for larval forms as well as the leeches. It is proposed that the HAI using A. uranoscopus and C. pretoriae should not be employed for future studies because not all variables can be used due to the small size of these fish species. It is proposed that the study should be done seasonally at all localities to detect differences in the occurrence of parasites in relation to the seasonal water quality. Thesis (M.Sc. (Zoology)) -- University of Limpopo, 2023

2023-01-01T00:00:00Z