TEMPORAL CHANGES IN LENGTH-WEIGHT RELATIONSHIPS OF SCIAENIDAE (PISCES: TELEOSTEI) SPECIES IN SOUTH BRAZIL

This study reports the importance to evaluate the length-weight relationships (LWR) across the years. We evaluate the LWR for 8 Sciaenidae species of Paranaguá Estuarine Complex, South Brazil, sampled between 2016 and 2018 by bottom trawls similar to the used by artisanal fisheries in this region. There were differences between growth type among the years for 5 species, and all species showed differences in the slope of LWR in at least one year. These results show the importance of fauna and fisheries monitoring programs to better evaluate the population dynamics and fisheries stocks. Keywords: estuarine fish, fisheries biology, marine fish, sciaenid, weight-length relationship

Length–weight relationship of Charybdis callianassa Herbst, 1789 (Decapoda: Brachyura) in relation to sex and carapace length along the Mumbai coastal water, India

Background The present study was performed to determine carapace length–body weight relationship of Charybdis callianassa. In fisheries biology, length–weight relationships are important as they allow for the calculation, by creating a mathematical equation between the two, of the total weight of the fish in a particular group in fish. Such information is helpful for fishery scientists to research the dynamics of development and populations and for public agencies that can maintain and preserve these resources sustainably. Results A study on the carapace length–body weight relationship of Charybdis callianassa (Herbst, 1789) was made on the northwest coast of India for the first time. The study was based on experimental trawl fishing conducted fortnightly from August 2019 to March 2020. A total of 479 specimens, including 262 males and 217 females from fishing trawler, were examined for their carapace length and total weight. The carapace length ranged from 2.69 to 3.54 cm, and the total weight from 5.26 to 7.36 g. This analysis revealed that the crabs exhibited negative allometric development, as shown by average exponents 'b' = 2.71 for pooled data with high coefficient (r) = 0.91 and r2 = 0.83. Conclusions The carapace length–body weight relationship of Charybdis callianassa in relation to sex and carapace was studied in the Mumbai coastal water, India. We found major differences in the average “r2” values of species reported for males (0.89), females (0.79) and pooled data (0.83). Such kind of study is essential for fisheries biology to comprehend the differences in circumstances in small and large specimens that vary with environmental conditions and seasons.

Reproductive Biology of Oci Fish Selaroides leptolepis in Tomini Bay

Local people name Selaroides leptolepis distributed in Tomini Bay as Oci Fish. A study of the fish reproductive biology, which is one aspect of fisheries biology, is crucial to support the implementation of sustainable Oci Fish resource management policies. This study aims to determine the average length at first maturity, gonad maturity stages, and fecundity of the fish in Tomini Bay. Sampling was carried out using a stratified random sampling method from the catches of the fishermen landed in Fish Landing Base Kampung Tenda, Gorontalo City. The time interval sampling was conducted per month during April, May, and June 2020. Fish and egg samples preserved using ice cubes and a 10% formaldehyde solution correspondingly. The results of the study showed that the Oci Fish in Tomini Bay had a length range of the first maturity between 166 and 174 mm with a gonad maturity index ranging from 1.773 to 2.760%. The average fish fecundity was 16623 ± 4850 eggs.

Ichthyofauna of Lake Buaya, South Sulawesi

Lake Buaya is one of the lakes located in the central part of South Sulawesi. Information about ichthyofauna biodiversity in this lake does not yet exist. Therefore, this study was conducted to analyze species composition, relative abundance, diversity index, evenness index, and dominance index, fish caught in the waters of Lake Buaya. This research was conducted in March to May 2019. Sampling was carried out four times over two months using a fishing gear with a mesh size of 2 inches. Sample analysis was carried out at the Fisheries Biology Laboratory, Faculty of Marine Sciences and Fisheries, Hasanuddin University. During the study 328 fish were found that belong to 12 species and 9 families. The highest abundance of individuals and relative fish abundance was found in Trichopodus pectoralis (snakeskin gourami). The range of diversity index, evenness index, and dominance index were 2,11–2,35, 0,85–0,95, and 0,10–0,15, respectively.

Hubungan Panjang dan Bobot Ikan Bigeye Tuna (Thunnus obesus Lowe, 1839) Di Perairan Samudera Hindia

The potential of fisheries resources in Indonesia is 9,931 million tons per year, with the highest potential being in WPP 718 of 1,992 million tons / year (20%), in WPP of 1,228 million / year (12%) and in WPP 711 of 1,143 million tons / year (12%). Bigeye Tuna (Thunnus obesus) is one of the leading commodities from the fisheries sub-sector which is commonly consumed both locally and export. Cilacap Ocean Fishery Port (PPS), Cilacap Regency, is one of the Bigeye Tuna (Thunnus obesus) fish landings caught from the Indian Ocean. This study aims to find out information on the long-term weight ties of Bigeye Tuna (Thunnus obesus) captured from the Indian Ocean and landed at PPS Cilacap, Central Java. According to Cilacap PPS (2014), Bigeye Tuna (Thunnus obesus) fish is one of the large pelagic fish species with the most catches after skipjack fish from all landed fish. The results of the analysis of the relationship between weight weights show that the growth pattern of big eye tuna (Thunnus obesus) is allometric negative (b <3). In fisheries biology, this long-weight relationship of fish is one of the information that needs to be known in terms of fisheries resource management.