Habitat differences and spatial and temporal separation in reproductive swarming among sympatric nereidid polychaetes were examined in an estuary of the Omuta-gawa River, Kyushu, Japan by annual periodical sampling from December 2003 to January 2005. Benthic adults of Tylorrhynchus osawai and Hediste diadroma occupied mainly the upper reaches of the estuary, whereas those of H. japonica usually inhabited the middle reaches, though their distributions overlapped. Reproductive swarming of mature adults occurred in the estuary just after high tide at night during spring tides in four nereidids: H. japonica (in the middle and lower reaches from late December to late February), H. diadroma (throughout the whole estuary from middle December to late April), T. osawai (in the middle reaches and another estuary from late October to late December), and Nectoneanthes oxypoda sensu Imajima, 1972 (in the lower reaches in late April and early May). This result shows that temporal separation of reproductive swarming may act as a reproductive isolation mechanism among these nereidids, except for H. japonica and H. diadroma. Simultaneous swarming and mass-spawning of the two Hediste species were commonly observed in the middle and lower reaches from late December to early February, suggesting the absence of a pre-spawning barrier to reproductive isolation between them. We found no difference in spawning behavior between H. japonica and H. diadroma. Males of both species seemed to participate in swarming earlier than females.

Adsorption of procion red and congo red dyes using microalgae Spirulina sp was conducted. Spirulina sp was obtained by cultivation and production in laboratory scale. Spirulina sp was used as adsorbent for adsorption of dyes. Adsorption process was studied by kinetic and thermodynamic in order to know the adsorption phenomena. The results showed that kinetically congo red is reactive than procion red on Spirulina sp. On the other hand, thermodynamically procion red was stable than congo red on Spirulina sp which was indicated by adsorption capacity, enthalpy, and entropy.

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This study aims to determine the diversity of butterflies in protected forest of Pulau Panas Village, Tanjung Sakti Pumi, Lahat, South Sumatra. The research was conducted in October -November 2020. The research sites were three different types of habitat, namely primary forest, riverbanks, and transitional or ecotone area of forests and plantations. Data collection uses exploration or roaming techniques following a 300-meter-long path with a width of 2 m to the right and 2 m to left in each habitat type using insect nets. The results obtained 61 species of butterflies (Lepidoptera: Rhopalocera) belonging to 5 families (8 species of Papilionidae, 11 species of Pieridae, 33 species of Nymphalidae, 3 species of Hesperiidae and 6 species of Lycaenidae). The highest diversity (Shannon index) is in primary forest habitat with H'= 3.67; followed by transitiononal forest and plantation areas with H' = 3.62, while the lowest diversity index is riverbanks with H'= 3.24. The evennes index of the species is almost the same (E>0.9). The highest species richness was found in primary forest (Dmg: 9.75). Protected butterfly species (according to the Decree of Ministry of Environment and Forestry No. 106 year 2018) found in this study is Troides helena.

Kinetic and thermodynamic adsorption study of Co(II) ions from aqueous solutions by dried Spirulina sp. biomass was investigated in the batch system. The Spirulina sp. was isolated and cultured from algae swamp ecosystem in South Sumatera. The adsorption properties of Co(II) onto dried Spirulina sp. biomass was studied by the influence of contact time, initial metal ion concentration and reaction temperature. The experimental results were the rate of adsorption followed the second-order kinetic model with the rate of reaction k 2 is 0.023 g mg-1 min-1 and the thermodynamic studies showed that the adsorption was well fitted to the Langmuir's model, and the amount of Co(II) removed from solution increased with increasing Co(II) concentration with the higher adsorption energy was 10.38 kJ/mol at 30 °C.