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Distribution pattern of black fly (Diptera: Simuliidae) assemblages along an altitudinal gradient in Peninsular Malaysia.

Ya'cob Z, Takaoka H, Pramual P, Low VL, Sofian-Azirun M - Parasit Vectors (2016)

Bottom Line: Simulium sp. (nr. feuerborni) and S. asakoae were found from middle to high altitudes (711-1813 m).Regression analysis between species richness and PCs revealed that the species richness was significantly associated with wider, deeper and faster streams at low altitude, normal water temperature (23-25 °C), low conductivity, higher discharge, more canopy cover and riparian vegetation and with larger streambed particles (F = 20.8, df = 1, 422, P < 0.001).Forward logistic regression indicated four species were significantly related to the stream variables (S. whartoni, Simulium sp. (nr. feuerborni), S. tani and S. angulistylum).

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. xuehy_perdana@yahoo.com.

ABSTRACT

Background: Preimaginal black flies (Diptera: Simuliidae) are important components of the stream ecosystem. However, there has been limited research undertaken on the vertical distribution of preimaginal black flies and their associated ecological factors. Stream conditions are generally variable along the altitudinal gradient. Therefore, we conducted an in-depth entomological survey to investigate the simuliid distribution pattern along an altitudinal gradient in Peninsular Malaysia.

Methods: A total of 432 collections were performed in this study (24 samplings at each of 18 fixed-streams at monthly intervals) from February 2012 to January 2014. Larvae and pupae attached on aquatic substrates such as grasses, leaves and stems, twigs, plant roots and rocks were collected by hand using fine forceps. Stream depth (m), width (m), velocity (m/s), water temperature (°C), acidity (pH), conductivity (mS/cm) and dissolved oxygen (mg/L) were measured at the time of each collection.

Results: A total of 35 black fly species were recorded in the present study. The most frequently collected species were Simulium tani (31.7%) and S. whartoni (21.5%), while the relatively common species were Simulium sp. (nr. feuerborni) (16.2%), S. decuplum (15.5%), S. angulistylum (14.8%), S. bishopi (13.2%) and S. izuae (11.8%). Total estimated species richness ranged between 39.8 and 41.3, which yielded more than 80% of sampling efficiency. Six simuliid species were distributed below 500 m, whereas eight species were distributed above 1400 m. Simulium sp. (nr. feuerborni) and S. asakoae were found from middle to high altitudes (711-1813 m). Simulium whartoni, S. brevipar and S. bishopi were distributed widely from low to high altitudes (159-1813 m). Regression analysis between species richness and PCs revealed that the species richness was significantly associated with wider, deeper and faster streams at low altitude, normal water temperature (23-25 °C), low conductivity, higher discharge, more canopy cover and riparian vegetation and with larger streambed particles (F = 20.8, df = 1, 422, P < 0.001). Forward logistic regression indicated four species were significantly related to the stream variables (S. whartoni, Simulium sp. (nr. feuerborni), S. tani and S. angulistylum). Canonical correspondence analysis indicated that the temperature, stream size and discharge were the most important factors contributing to the separation of the stream sites from different altitude and hence are the predictors for the distribution of black fly species assemblages.

Conclusions: This study has provided insight into the distribution pattern of preimaginal black fly assemblages along an altitudinal gradient in Peninsular Malaysia. This study could deepen our knowledge on the ecology and biology of the specialised taxa in response to environmental changes.

No MeSH data available.


Related in: MedlinePlus

Ordination diagram of the first two axes of canonical correspondence analysis (CCA) of the 35 black fly species in Peninsular Malaysia
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Fig7: Ordination diagram of the first two axes of canonical correspondence analysis (CCA) of the 35 black fly species in Peninsular Malaysia

Mentions: An ordination diagram for 18 fixed-stream sites and species are presented in Figs. 6 and 7, respectively. CCA indicated that temperature, stream size and discharge were the most important factors in differentiating streams from different altitudes. Therefore, these factors are good predictors for black fly species assemblages. The relationship between species and stream variable conditions was high (> 0.569) for the first three canonical axes, indicating that the variables used in this study were strongly related to black fly species assemblage. Temperature was the most important factor on the CCA axis 1. Species that associated with normal stream temperature were S. cheongi and S. trangense. The bottom left panel of the biplot is characterized by streams with wider and higher discharge. These sites were predominated by S. tani, S. nobile and S. jeffreyi. The upper right side of the biplot is composed of sites with lower discharge and smaller streams. Black fly species found predominantly at these sites were S. bishopi, S. izuae and S. longitruncum. The bottom right panel of the biplot is characterized by low water temperature, which is characteristic of high altitude streams. Black flies predominating at these sites were S. asakoae, S. caudisclerum and Simulium sp (nr. feuerborni) (Fig. 7).Fig. 6


Distribution pattern of black fly (Diptera: Simuliidae) assemblages along an altitudinal gradient in Peninsular Malaysia.

Ya'cob Z, Takaoka H, Pramual P, Low VL, Sofian-Azirun M - Parasit Vectors (2016)

Ordination diagram of the first two axes of canonical correspondence analysis (CCA) of the 35 black fly species in Peninsular Malaysia
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4837513&req=5

Fig7: Ordination diagram of the first two axes of canonical correspondence analysis (CCA) of the 35 black fly species in Peninsular Malaysia
Mentions: An ordination diagram for 18 fixed-stream sites and species are presented in Figs. 6 and 7, respectively. CCA indicated that temperature, stream size and discharge were the most important factors in differentiating streams from different altitudes. Therefore, these factors are good predictors for black fly species assemblages. The relationship between species and stream variable conditions was high (> 0.569) for the first three canonical axes, indicating that the variables used in this study were strongly related to black fly species assemblage. Temperature was the most important factor on the CCA axis 1. Species that associated with normal stream temperature were S. cheongi and S. trangense. The bottom left panel of the biplot is characterized by streams with wider and higher discharge. These sites were predominated by S. tani, S. nobile and S. jeffreyi. The upper right side of the biplot is composed of sites with lower discharge and smaller streams. Black fly species found predominantly at these sites were S. bishopi, S. izuae and S. longitruncum. The bottom right panel of the biplot is characterized by low water temperature, which is characteristic of high altitude streams. Black flies predominating at these sites were S. asakoae, S. caudisclerum and Simulium sp (nr. feuerborni) (Fig. 7).Fig. 6

Bottom Line: Simulium sp. (nr. feuerborni) and S. asakoae were found from middle to high altitudes (711-1813 m).Regression analysis between species richness and PCs revealed that the species richness was significantly associated with wider, deeper and faster streams at low altitude, normal water temperature (23-25 °C), low conductivity, higher discharge, more canopy cover and riparian vegetation and with larger streambed particles (F = 20.8, df = 1, 422, P < 0.001).Forward logistic regression indicated four species were significantly related to the stream variables (S. whartoni, Simulium sp. (nr. feuerborni), S. tani and S. angulistylum).

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. xuehy_perdana@yahoo.com.

ABSTRACT

Background: Preimaginal black flies (Diptera: Simuliidae) are important components of the stream ecosystem. However, there has been limited research undertaken on the vertical distribution of preimaginal black flies and their associated ecological factors. Stream conditions are generally variable along the altitudinal gradient. Therefore, we conducted an in-depth entomological survey to investigate the simuliid distribution pattern along an altitudinal gradient in Peninsular Malaysia.

Methods: A total of 432 collections were performed in this study (24 samplings at each of 18 fixed-streams at monthly intervals) from February 2012 to January 2014. Larvae and pupae attached on aquatic substrates such as grasses, leaves and stems, twigs, plant roots and rocks were collected by hand using fine forceps. Stream depth (m), width (m), velocity (m/s), water temperature (°C), acidity (pH), conductivity (mS/cm) and dissolved oxygen (mg/L) were measured at the time of each collection.

Results: A total of 35 black fly species were recorded in the present study. The most frequently collected species were Simulium tani (31.7%) and S. whartoni (21.5%), while the relatively common species were Simulium sp. (nr. feuerborni) (16.2%), S. decuplum (15.5%), S. angulistylum (14.8%), S. bishopi (13.2%) and S. izuae (11.8%). Total estimated species richness ranged between 39.8 and 41.3, which yielded more than 80% of sampling efficiency. Six simuliid species were distributed below 500 m, whereas eight species were distributed above 1400 m. Simulium sp. (nr. feuerborni) and S. asakoae were found from middle to high altitudes (711-1813 m). Simulium whartoni, S. brevipar and S. bishopi were distributed widely from low to high altitudes (159-1813 m). Regression analysis between species richness and PCs revealed that the species richness was significantly associated with wider, deeper and faster streams at low altitude, normal water temperature (23-25 °C), low conductivity, higher discharge, more canopy cover and riparian vegetation and with larger streambed particles (F = 20.8, df = 1, 422, P < 0.001). Forward logistic regression indicated four species were significantly related to the stream variables (S. whartoni, Simulium sp. (nr. feuerborni), S. tani and S. angulistylum). Canonical correspondence analysis indicated that the temperature, stream size and discharge were the most important factors contributing to the separation of the stream sites from different altitude and hence are the predictors for the distribution of black fly species assemblages.

Conclusions: This study has provided insight into the distribution pattern of preimaginal black fly assemblages along an altitudinal gradient in Peninsular Malaysia. This study could deepen our knowledge on the ecology and biology of the specialised taxa in response to environmental changes.

No MeSH data available.


Related in: MedlinePlus