Habitus Aquatica

Komunikasi singkat: Keberadaan alga hijau koin, di Pesisir Lhok Bubon, Samatiga, Aceh Barat

Eka Lisdayanti — 2024-06-15

This study aims to report the diversity of the Halimeda genus on the West Aceh coast. Data was collected in the Lhok Bubon Coastal intertidal area, Samatiga, West Aceh Aceh Province. Macroalgae samples were collected using the cruising method along the beach with a depth of 1-2 m at low tide. The Halimeda genus found four species, namely Halimeda macroloba, Halimeda macrophysa, Halimeda incrassata, and Halimeda simulans. Halimeda macroloba was found to have a whitish-green talus. Halimeda macrophysa samples have irregular talus branches. Description Halimeda incrassata at the study site is light green, and the holdfast is attached to the sandy substrate to form large sediment clumps. Halimeda simulans were found to be linked to sand, which tends to have a finer texture. The results of this report provide information that Lhok Bubon Beach, West Aceh, has macroalgae potential that needs further study.

Pendugaan Parameter Dinamika Populasi Ikan Selar crumenophthalmus yang didaratkan di Pangkalan Pendaratan Ikan Tenda Gorontalo

Nuralim Pasisingi — 2024-07-01

This research aimed to determine the age group, growth, mortality, and yield per recruitment (Y/R) of Selar crumenophthalmus landed at Gorontalo City Tenda Fish Landing Base. A total of 1020 samples were collected randomly from fishermen who landed their catches at Tenda Fish Landing Base. The results of research based on sampling carried out twice a week from March to May 2023 showed that there were three age groups of S. crumenophthalmus. The percentages for age groups I, II, and III were 39.90%, 55.30%, and 4.30%, respectively. The asymptote length of the fish L∞ = 269.4 mm, the growth rate of the fish K = 0.55 and the theoretical age of the fish t₀ = -0.1616 years. The natural mortality M = 0.48 was smaller than fishing mortality F = 0.85, total mortality Z = 1.33 per year, and total exploitation rate E = 0.64 per year. The Y/R value was 0.106 grams/recruitment with an exploitation rate of 0.608 per year.

Utilization of Natural Anesthesia Materials in Closed-System Transportation of Post-Larvae Fish: Article Review

Zahrah Alifia Ghaida Anrose — 2024-08-02

Fish seed is a primary factor in the success of aquaculture activities. However, aquaculture farmers are finding it difficult to obtain quality seed suppliers, leading to a lack of supply in some areas. This causes farmers to rack their brains. One way that can be done is by conducting a closed-system of wet transportation from a quality seed supplier. Chemical and natural anesthetics can be used to keep fish seeds alive in a healthy condition and minimize mortality during transportation. Chemical synthetic anesthetics have disadvantages if used continuously because they can reduce immune function and interfere with the health of the seed. Therefore, a literature review was conducted to provide information on a variety of natural compounds that can be used as a substitute for synthetic chemicals in anesthetizing fish seed during the closed-system of wet transportation using the literature study method. Natural ingredients used as anesthetics to replace synthetic chemicals are clove oil, citronella oil, tuba root extract, cassava extract of inner accession, papaya leaf extract, keben fruit, bandotan leaf extract, and guava leaf extract. Based on these natural anesthetic ingredients, the tree most effective types were identified. Cassava extract of inner accession yielded the most optimal results for transporting tilapia seeds with a survival rate of 100%. Additionally, papaya leaf extract provided the best results for tiger grouper seeds survival at 100%, while tube root extract showed a 98.3% survival rate for tilapia seeds.

Phytoplankton diversity and relationship with water quality of Cikoncang Reservoir, Lebak Regency

Ali Akbar Maulana — 2024-08-27

Phytoplankton are aquatic biota that have a rapid reaction to changes in water quality. Increased activities such as tourism and KJA in Cikoncang Reservoir can potentially reduce water quality. Phytoplankton is a bioindicator of water quality, phytoplankton diversity can describe water conditions. The purpose of the study was to analyze phytoplankton diversity, water quality, and the relationship between diversity and water quality of Cikoncang Reservoir. The research was conducted in March and April 2023. There were 5 research stations taken based on the purposive sampling method. Phytoplankton diversity is generally included in moderate diversity with a stable community and the distribution of individuals of each species with a range of values of 1.857–2.122. Based on the saprobity index, it can be seen that the Cikoncang Reservoir waters are included in moderate to light pollution. Based on PCA analysis, diversity has a positive relationship or correlates with brightness, temperature, DO, pH, nitrate, and TDS.

Occurrence of biennial sporophytes of the kelp Saccharina japonica in Hokkaido, Japan

Tadashi Kawai — 2024-09-17

Recent studies suggest that relict communities of Saccharina japonica var. ochotensis are rarely observed in southwestern Hokkaido, where S. japonica. var. religiosa is generally distributed. Previous research has mainly focused on the morphology of these species, and field survey data is very limited. In the present study, relict S. japonica var. ochotensis communities were observed only near the estuaries of larger rivers, specifically in estuarine areas where bedrock is present and the seashore has a gentle gradient slope. The biomass and size (length, width, and weight) of annual and biennial relict S. japonica. var. ochotensis were recorded. The carbon/nitrogen ratio of the kelp sporophytes was analyzed, and relatively lower values were observed in the relict community of this species. This information may help in the maintenance of kelp beds in southwestern Hokkaido and the wise utilization of relict S. japonica var. ochotensis in the estuarine areas of southwestern Hokkaido, Sea of Japan.