ARTICLE | doi:10.20944/preprints202207.0085.v1
Subject: Biology, Other Keywords: Crown of thorns starfish (CoTS); actinomycetes; venom extract; anti-enzymatic; antibacterial activity
Online: 6 July 2022 (04:03:02 CEST)
Crown of thorns starfish (Acanthaster planci) are coral predators with advantages of having toxicity in their venom and tissue regeneration capabilities. With all these characteristics, only a handful of studies have highlighted the association of microorganisms with this organism. Crown of thorns starfish are common in Fiji and their analyses of microbial diversity for secondary metabolites could be of great interest to the scientific community. This study is an attempt to investigate Fijian-based A. planci for their venom and associated actinomycetes antibacterial activity and further identify the type of enzymes present in the crude venom extract. The CoTS venom extract (0.192 g) harbor enzymes such as gelatinase, caesinase, and amylase. An abundant and potent actinomycete strain, represented as FJA1 showed antibacterial activity against Enterococcus faecium with an inhibition zone of 10 mm. Moreover, all pathogenic test microorganisms were resistant against concentrations of 500 µg and 1 mg of A. planci venom extract.
ARTICLE | doi:10.20944/preprints202208.0149.v1
Subject: Biology, Ecology Keywords: Honeyeater; foraging behaviour; diversity; human activity; avifauna
Online: 8 August 2022 (10:28:15 CEST)
Forests are increasingly becoming fragmented and declining due to natural causes and human-induced activities. The latter creates an imbalance which put the survival of vulnerable species such as those of avifauna at risk. Honeyeaters are group of birds common in Fiji, with certain species strictly confined to specific habitats. This study is an attempt to compare the abundance and foraging behaviours of three sympatric honeyeaters namely Kikau wattled honeyeater, Orange-breasted myzomela and Giant honeyeater at two contradicted sites (USP campus and Colo-i-Suva Forest Reserve). The survey was carried out using point count method along three different transect routes of approximately 2 Km on each study sites . A higher species diversity and abundance was observed in Colo-i-Suva Forest Reserve than in USP campus. Kikau wattled honeyeater are more populated at USP campus due to adequate nectar-producing plants. Whereas both Orange-breasted myzomela (highly adaptable bird species) and Giant honeyeater (forest specifics) are frequent in Colo-i-Suva Forest Reserve. All exhibited a wider range of foraging techniques across forest vertical strata and plant species, except for Giant honeyeater (not observed). The statistical analysis showed that there is a significant difference (p < 0.05) in abundance as well as between the number of honeyeater species in both sites across the forest vertical strata. However, there is no significant difference in the foraging behaviour and the number of honeyeaters found foraging on diverse plant species (p > 0.05).