Scoop Nets Research Articles

Length-weight relationship for Potamotrygon wallacei (Carvalho, Rosa and Araújo, 2016) caught in the middle Negro River, Barcelos, Brazilian Amazon.

This research aimed to estimate the length-weight ratio (LWR) of the stingray Potamotrygon wallacei, known locally as the cururu, which was caught in streams and lakes in the middle Negro River region, Amazonas, Brazil. The stingrays were captured during the night (from 11 pm to 1 am) near the shores of streams and lakes, through active search using wooden canoes, head lanterns and scoop nets. The samplings were carried out in November 2017 (5 days), February (8 days), March (3 days) and April (2 days) of 2018, totaling 18 days of sampling. The total fresh weight was measured to 0.1 g of accuracy and the disc width to 0.1 cm accuracy. The parameters a and b of the equation W=a.DWb were estimated. This study provides new maximum length data for the cururu stingray.

Short Notes on The Diversity of Butterflies (Order: Lepidoptera) at Selected Residential Areas in Sematan, South-Western Sarawak

Diversity and abundance of butterflies in Sematan area of South-Western Sarawak are studied. In Borneo, 944 different species of butterflies have been documented. In tropical countries, butterflies are essential for monitoring ecological pollination, part of food chain development, temperature change and the degradation of the environment. The study was carried out in order to better understand the presence and variety of butterflies in residential areas at Sematan. The natural vegetation of the area consists of shrubs, herbs, grasses, and tall trees such as Family Malvaceae. Aerial scoop nets were used for the collection in eight residential areas in Sematan. A total of 515 specimens belonging to 63 genera and six families were identified. The family Nymphalidae is the most abundant with 35 genera and 61 species. The family Nymphalidae has the highest Shannon-Wiener Index at 2.63 and the Simpson Diversity Index of 0.92. Nymphalidae are significant in abundance and common species widely distributed in the lower elevation of coastal areas. The occurrence of available adult plant resources and larval host plants contributed to the high diversity of Nymphalidae butterflies. Findings from this study are hoped to contribute to the existing data collection of butterflies especially in Sematan, and for future management and conservation of the native butterflies in Sematan.

Finfish fishery of Ashtamudi Estuary, India- A Ramsar site of International significance

The finfish catch structure of Ashtamudi Estuary, a Ramsar site of international importance was assessed from May 2019 to April 2020 covering ten major landing centers (Sakthikulangara, Sambranikodi, Mammottil kadavu, Ashtamudi, Perumon, Kurismmood, Cherikadavu, Arinalloor, Vellimon and Muttom). The annual finfish landings was estimated as 195.4 tonnes, contributed by 148 species of finfishes and a single species of Elasmobranch. Gill nets (51%) were the dominant gear in the finfish landings followed by scoop nets and hook and lines (20%), seine nets (15%), stake nets and Chinese dip nets (8%) and cast nets with (6%). The highest landing was recorded in the month of August (20.71 tonnes). The major finfish groups that contributed to the fishery of Ashtamudi Estuary were Cichlids (24.08%), catfishes (13.72%) and Mullets (10.22%). The study revealed the decline in the finfish landings from its estimated quantity of 3462 tonnes (2000–2001) might be attributed to the (1) decrease in number of active fishers, (2) declining mangrove cover, (3) loss of wetland area, (4) unsustainable fishing practices and (5) increasing anthropogenic pressures from urbanization of Kollam Corporation . In this context, the paper also discusses various management measures to improve the fish catch from the estuary in a sustainable way.

Freshwater ichthyofauna of wetlands in Tablas Island, Romblon, The Philippines

The Philippines is a hotspot for biological variety and a hub for endemism on a worldwide scale. Despite this, most of the research has focused on terrestrial and marine biodiversity, with little knowledge of freshwater fish diversity and status. There has been no systematic research on these species in Romblon. As a result, this research was conducted. This study aims to evaluate the freshwater fishes of Tablas Island, Romblon, utilizing modified hoop nets, gill nets, scoop nets, and hook and line. A total of 44 species belonging to 36 genera and 19 families were identified. They are often found in rivers, and streams, while most of them are native to the Philippines, where they are being eaten by natives. The IUCN Red List placed the majority of these species in the Least Concern category. The dominating species was Gambusia affinis, with Giuris margaritaceus being the most frequent across all sites. A new locality record of an indigenous minnow species (Barbodes hemictenus) was found. The ichthyofauna of Tablas Island is diverse, with local species dominating. Only two introduced species were identified as threatened (Vulnerable). On the other hand, the rest were classified as Least Concern, Unknown, Not Evaluated, and Data Deficient.

Jellyfish fisheries along the Gujarat coast, India: Status and challenges

The study exemplified jellyfish fisheries along India's Northwest coast, constituted by two emerging Scyphozoan species, Catostylus perezi and Rhopilema hispidum, which swarmed in and around the Gulf of Kutch. Jellyfishing operations were small-scale and operated by motorised crafts, primarily using scoop nets. The fishing season fluctuated between March-May and October-December. The jellyfish landings from November 2017 to February 2020 were 13569.95 metric tonnes (82.1% C. perezi and 17.9% R. hispidum) of oral arms contributed by Jakhau (67.37%) and Okha (32.63%) jellyfish focal stations, making it a nascent small-scale commercial fishery, which indicates a shift in harvest from fish to jellyfish. In 2018, the estimated value of landed jellyfish (6538.4 metric tonnes) at first sale was ₹78.46 million ($1.14 million). The jellyfishing closures due to socio-sectoral conflicts and unsuitable weather conditions were considered for a 30.71% reduction in 2019. After processing using salt and alum, the semi-dried oral arms of C. perezi and R. hispidum were locally traded as salted-banana-jhar and salted-flower-jhar, respectively. The majority (65%) of processed jellyfish were exported to China, and the rest to other Asian countries from Mundra and Pipavav ports. The myriad challenges were discussed in the nascent jellyfish fisheries. A conceptual plan was advised for developing jellyfish research as a priority area in India that may help minimise knowledge gaps and support management actions. The study recommended jellyfish as future food and secondary raw material with better harvesting and processing practices. A co-management with a precautionary approach was suggested for the sustainability of jellyfish resources.

Population dynamics of blood clams Tegillarca granosa in Kendari Bay, Southeast Sulawesi, Indonesia

Abstract. Bahtiar, Purnama MF, Kasim M, Ishak E. 2022. Population dynamics of blood clams Tegillarca granosa in Kendari Bay, Southeast Sulawesi, Indonesia. Biodiversitas 23: 5084-5092. Blood clams (Tegillarca granosa) are bivalves found in the intertidal areas of ??Kendari Bay which are subjected to ecological stresses. Therefore, this study aims to determine the population dynamics of blood clams in Kendari Bay, Southeast Sulawesi, in terms of their size structure, growth, mortality, and exploitation level from March 2018-February 2019. The samples were collected with scoop nets in ten 5x5 m2 transects. Water quality parameters were monitored every sampling period. The length of the shells was measured using a caliper with an accuracy of 0.05 mm. The data were processed using the Bhattacharya method, inverse von Bertalanffy model, length-converted catch curve, and Pauly's empirical data, respectively. All of the methods were accommodated in the FiSAT II version 3.0 program. Results showed that the blood clams were divided into 2-3 size categories, namely young adult, adult, and old age, where the most dominant was the adult size group. The growth pattern of the samples was based on the equation Lt = [6.67-(6.67-0.025)] e-0.72t. The majority of the blood clams were distributed in the 1-2 years age group. Natural, fishing and total mortalities (Z) of the blood clams were 2.18 yr-1, 0.29yr-1, and 3.09yr-1, respectively, with an exploitation rate (E) of 0.29 (underexploited).

The Diversity of Fish in Seagrass Beds and Bare Sand channel In Tablolong Waters, Kupang Regency

Seagrass ecosystems in Tablolong waters have important values related to the availability of fish resources. However, this seagrass meadow experiences a lot of fragmentation in the form of empty sand areas without vegetation (bare sand), both in the form of channels and tidal pools which provide many small living spaces (microhabitats) that are interesting for aquatic ecology studies. The aim of this research was to analyze the diversity and dominance of fish species in the seagrass beds and bare sand channels, as well as to determine the dominant species of seagrasses in the seagrass beds. The study was conducted through direct observation by catching fish specimens using gillnets (# 1.5 inches and #1.25 inches, @ length 20 m x height 1.5 m) and scoop nets three (3) times sampling with time intervals. 7-10 days in the time period of October-November 2021. The results showed that the seagrass beds in the Tablolong Waters are classified as heterospecific from at least 6 (six) seagrass species with an average density of all species reaching 219.2 stands/m2 and an average cover of 40.0% (medium level of cover) where Thalassia hemprichii was the dominant seagrass species in terms of density value (more than 50%of total species) and cover value almost 40% of total species. The fish collection obtained as a whole consisted of 22 fish species from 17 families with 86 individuals where the fish community in the seagrass beds (9 species, 8 families, 17 individuals) was recorded to be lower than the fish community in the empty sand tunnel (13 species, 11 families, 49 individuals), each with a ratio of 41%:59% in species, a ratio of 47%:65% in families and a ratio of 43%:57% in the number of individuals. The status of the fish species that dominates was the occasional visitor fish of 90% (20 species) compared to seasonal visitor fish and whole life resident fish of 5% (1 species). The index value of fish species diversity in seagrass beds was moderate (H’ 2) which was lower than the fish community in empty sand tunnels which was high (H’ 4) and the total number of fish species on Tablolong beach was high (H’ > 4). The fish species dominance index value showed that in both fish in seagrass beds (D 0.28), in empty sandtunnels (D 0.11), and the whole area (D 0.25) in Tablolong waters there were no dominant fish species. So that the structure of the fish community tends to be stable or the diversity of fish species tends to be high.

Length–weight relationships of seven small indigenous fish species from the Tapti River in peninsular India

AbstractLength–weight relationships of seven small indigenous fishes collected from the middle and lower stretch of the Tapti River in India were determined. The specimens were caught with drag nets (0 mm mesh size), gill nets (10–20 mm knot‐to‐knot mesh length) and scoop nets (0 mm) from the Maharashtra, and Gujarat state stretches of the Tapti River from November 2018 to December 2019. Digital calliper and digital balances were used to measure the total length (TL) and body weight (BW) of all fish specimens respectively. The growth coefficient b varied from 2.758 (Parambassis ranga) to 3.298 (Osteobrama cotio), and the LWRs were highly significant (p < .005). The present study established LWRs for the first time for seven fish species in the respective riverine habitat, including providing a new maximum length record for Corica soborna. The results of the present study will be useful for sustainable management and conservation of respective species in the river and its associated waterbodies.

REPRODUCTIVE ASPECT OF TINY SCALE BARB, Thynnichthys thynnoides (BLEEKER, 1852) AT RUI RIVER, PERAK, MALAYSIA

This study aims to understand the reproductive biology of Thynnichthys thynnoides at Rui River, Perak, Malaysia. A total sample of 175 individuals, including 83 from Kuala Rui (S1) and 92 from Air Ganda (S2), were collected from local artisanal fishers. Fish was caught using gill nets and scoop nets during migration and spawning seasons (i.e., November to December 2018). For each fish individual, the total length (TL), body weight (BW), and ovary weight (OW) were and. A Chi-square test was performed to evaluate the sex ratio of the studied population. Simple linear regression analysis was used to explain the relationship between absolute fecundity (FA) or relative fecundity (FR) with total length, body weight, and ovary weight. For a coefficient of determination (r2) and correlation coefficient (r), a regression equation was determined. The results showed that the TL of T. thynnoides varied from 13.3 to 20.3 cm, with a calculated mean of 16.78 ± 1.1 cm. Body weights ranged from 31.86 to 78.86 g, with an average body weight of 53.81 ± 10.1 g. The FA ranged from 14454 to 29531 (mean = 21112 ± 4612) eggs per fish, and the FR from this study ranged from 211 to 658 (mean = 358 ± 93), where the OW was more significantly correlated with the absolute fecundity (r>0.513; p<0.001) than other body metrics. Negative allometric growth of T. thynnoides was observed during this study. The overall ratio of the T. thynnoides was 1:0.82 (male: female). In conclusion, this study has shown that the fecundity of the fish population is declining, although the cause is still unclear. The knowledge of this study would help fisheries managers plan necessary regulations for sustainable fishery practice at the Rui and Perak rivers, specifically during the migration and spawning season of T. thynnoides.

Ichthyofaunal Diversity of the River Nun Estuary, Niger Delta, Nigeria

A study of the Ichthyofaunal diversity of the River Nun Estuary, Nigeria was conducted for one calendar year. This was done in order to update the inventory of the fish species and to specify distribution patterns in the River Nun ichthyofauna in order to establish some basis for pollution prevention and the conservation of these fish communities and their habitat. Fishes were collected monthly from six sampling sites of the River Nun Estuary with the help of local skilled fishers. Cast nets, scoop nets, gill nets, beach seine nets, pole seine nets, and hooks and lines were used for capturing fish. Different fish species were collected from fishers at the different fish landings. photographs were immediately taken with the help of a digital camera. Fishes brought to laboratory were preserved in 10% formalin solution. All fish species were identified to genus and species level using taxonomic keys and standard literature. 60 species of fish that belong to 48 different genera and 27 families were recorded during the study. The families Cichlidae and Gobiidae had the highest number of species (7 species each) followed by the families Claroteidae, Carangidae, Mugilidae, and Characidae (which had 4 species each), Polynemidae (with 3 species), and Clupeidae Tetraodontidae, Carangidae, Sclaenidae (with 2 species each). The families Hepsedae, Dasyatidae, Soleidae, Elopidae, Monodactylidae, Lobotidae, Periophthalmidae, Ophichthidae, Soleidae, Cynoglossidae, Tetraodontidae, Serranidae, Clupeidae, Carangidae, and Haemulidae had just one species. Ethmalosa fimbriata(Bonga shad) of the of the Order Clupeiformes and family Clupeidae was the most abundant species of the River Nun estuary, followed by Pseudotolithus (Foniticulus) elongates (Croaker) of the family Sclaenidae, Periophthalmus barbarous/ papilio (Atlantic mudskipper) of the family Periophthalmidae, Mugil curema (White mullet), Mugil bananensis (Banana mullet), and Liza grandisquamis (Sickle fin mullet) of the family Mugilidae. It can be concluded that the ichthyofaunal composition of the River-Nun compares favorably with other Rivers of similar relevance.There is no cause for concern by all stakeholders about its ecological health and its fishery. Keywords: Ichthyofauna, Diversity, Estuary, River-Nun, Niger Dela.

Short communication: Amphidromous goby postlarvae (penja) migration seasons and fisheries in West Sulawesi, Indonesia

Abstract. Nurjirana, Burhanuddin AI, Keith P, Haris A, Afrisal M. 2021. Short communication: Amphidromous goby postlarvae (penja) migration seasons and fisheries in West Sulawesi, Indonesia. Biodiversitas 23: 375-380. Several gobioid species have amphidromous migration patterns; adult gobies spawn in their freshwater habitat, embryos are carried by river currents to reach the sea where they undergo a planktonic phase lasting several months before migrating to estuarine and then freshwater (predominantly riverine) environments to grow and breed. Around the island of Sulawesi in Indonesia, these migrating postlarvae have various local names; in West Sulawesi they are collectively known as penja, a popular fisheries commodity, but data on their migration patterns are limited. This study aimed to determine penja migration seasons and document some aspects of the penja fisheries in West Sulawesi. The research was conducted in the lower reaches of five rivers: the Mapilli, Mandar, Teppo, Palipi, and Lariang rivers. Penja samples were collected from fishermen's catches using several types of fishing gear such as seser (scoop nets), dariq or bunde (push nets), panesser (casting net) and other traditional or artisanal fishing equipment. Samples were also collected from traditional markets. The postlarvae were measured and grouped based on morphological characters. The results showed temporal differences in migration patterns between the five study sites, while external morphology indicated the presence of several species in migrating penja schools. During the rainy season, populations with a more diverse morphology were found than during the dry season.

Diversity of Freshwater Fish in Fragmented Forest of Wilmar Oil Palm Plantation, Miri, Sarawak

The study was conducted in the river system located at Wilmar oil palm plantation in Miri, Sarawak. The objective of the study is to determine the fish species diversity and composition in the streams and rivers in the oil palm plantations. Fish were sampled using a variety of fishing methods, including, scoop nets, cast net, and gill nets of different mesh sizes (1.0, 1.5, 2.0, 2.5, 3.75 and 4.0 cm) from 2 to 7 of February 2014. A total of 326 individual fish including 32 species of native fishes and one species of non-native fish from 19 genera, seven families and five orders were collected from seven locations. The cyprinid fish represented 62.20% of the total fish caught and was found in all the rivers surveyed. About six endemic species in Borneo such as Barbonymus collingwoodii, Barbodes banksi, Barbodes sealei, Hampala bimaculata Nematabramis borneensis and Nematabramis everetti were identified. However, only one species from families Bagridae, Balitoridae, Clariidae, and Hemiramphidae was sampled from the study sites. The higher fish species composition found in streams and rivers of the oil palm plantation landscapes could be attributed to the conservation of some areas of the plantation as high conservation value forest (HCVF) status, which have provided suitable habitat for fish species within the plantation aquatic environments.

Diversity of freshwater fish in Forest Research Institute Malaysia (FRIM): A comparison of diversity between man-made and natural forest in Selangor, Malaysia

This present study aimed to investigate the diversity of freshwater fish in a planted forest within three tributaries, namely Sungai Kroh, Sungai Chemubong, and Sungai Cahaya, in the Forest Research Institute Malaysia (FRIM) campus. In this study, freshwater fish were sampled using a backpack electro-fisher and scoop nets along 100m transect lines for each sampling site (at upper, middle, and lower part) of the respective river. All individuals collected were examined and measured to identify at their species level. However, we found no fish presence in Sg. Cahaya across all sub-section of the tributary. Hence, the result of fish was based on two tributaries of Sg. Kroh and Sg. Chemubong. A total of 235 individual freshwater fish recorded in FRIM belong to 10 species comprising six families. The highest recorded family belongs to Cyprinidae (30%), followed by Channidae and Danionidae families with 20% respectively, whereas the other three family only represent 10% respectively. Shannon-Wiener indices showed that the highest diversity was recorded for Sg. Chemubong, H = 1.283, while the lowest was recorded for Sg. Kroh, H = 1.097. The highest Evenness index of fish species was detected for Sg. Chemubong, E = 0.5098 and the lowest for Sg. Kroh, E = 0.2994. We carried out a similarity analysis by comparing freshwater fish from adjacent natural forest reserves, namely Sungai Kanching Forest Reserve. Based on the presence-absence data, the species composition of the freshwater fish between the man-made forest (FRIM campus) and natural forest (Sungai Kanching Forest Reserve) was almost 82% similar based on the Sørensen similarity index. The discussion was made based on the available findings in this study to illustrate the freshwater ecosystem stability in a man-made tropical forest, for instance, in FRIM Campus.

EXTENT OF PARTICIPATION OF RURAL WOMEN IN FISHING COMMUNITY: APPROACHES TOWARD SUSTAINABLE LIVELIHOOD

Women’s contribution to small-scale fishing community is often unrecognized and the real benefits from their involvement in activities are not objectively assessed. This qualitative research study focuses on the women’s participation in fishing community in Aklan. The findings revealed that in most fishing activities, women’s role is significant. Women’s participation in fishing includes: net mending, sorting fish, fish vending, trading and market retailing and processing and preservation. Women also have been found directly involved in preparing cage and maintenance, procuring good quality seed, and stocking. Some women are also found to be selling fish on their own, and most vend by the public market and streets. Fishing is an occupation dominated by men because of the image that only men go to sea in their fishing boats. In most cases, women in fishing communities are not allowed to go with the fishing vessels, but this prohibition is tied mostly to the need for them to remain within the premises of the household so they can attend to their designated responsibilities in the home. Due to this, they have little direct involvement in fish capture. However they are involved in shell and fry gathering/gleaning, spear fishing in rivers, reef fishing using scoop nets, traps and fish baskets, all of which tend to be near-shore activities. Women’s participants’ family income has increased which is mostly used for food, health, and education as a very important positive aspect of change. Women’s participation in fishing community, according to the findings, ensures certain extent of social and economic empowerment in the rural societies. However, they expressed that they would like to sustain through bank and NGO loan, local moneylender and petty cash personal savings. KEY WORDS: Fishing Community, Income, Participation, Rural Women, Sustainable Livelihood

Role of the non-state sector in environmental education for the protection of marine mammal

Length weight relationships (LWRs) were estimated for five endemic/native fish species collected from five localities in the inland waters of Oman in 2020 including Aphaniops kruppi and A. stoliczkanus (Aphaniidae), Cyprinion muscatense (Cyprinidae: Barbinae), and Garra barreimiae and G. longipinnis (Cyprinidae: Labeoninae) using foldable shrimp and crab fishing traps (mesh size of 3*3mm) and scoop nets (mesh size of 3*3mm). The parameter of b for all five species was within the expected range of 2.5–3.5. as proposed for different fishes (except for female A. stoliczkanus ), and there were high and significant correlation coefficients for all species (0.931-0.972). Bailey’s ‘t’ test in the five studied species showed that b value significantly deviated from 3.

Survey on the Current Status of Small-Scale Artisanal Sea Cucumber Fishing in Kien Giang Province, Vietnam

This study was conducted to assess the status of small-scale artisanal sea cucumber fishing around the islands of Phu Quoc, Nam Du, and Hai Tac, located in Kien Giang Province, Vietnam. A total of 90 sea cucumber fishers were randomly interviewed from October 2018 to March 2019. Results indicate that most fishers (96.7%) consider sea cucumber fishing as an extra income and use simple fishing methods such as diving (free diving and snorkeling), gleaning, and scoop nets. Catch composition (% whole wet weight) comprises five species, of which low- and medium-value species are most commonly harvested, including Holothuria leucospilota (39.5%–58.2%) and Stichopus spp. (29.7%–48.4%), followed by Holothuria atra (7.3%–10.9%) and two high-value species that are rarely found, that is, Holothuria scabra (2.6%–6.6%) and Holothuria nobilis (1.2%–1.6%). Current catch rates for an average fishing trip are 25.8–37.6 kg wet weight per diver, which has declined by 60%–95% over the past 10 y, indicating heavy overexploitation. Currently, the exploitation of sea cucumber in Kien Giang has encountered some difficulties, such as unusual weather, the drastic depletion of high-value stocks, and unstable selling price. This information will be useful for further research related to planning effective management programs for sea cucumber fisheries in the region.

Freshwater Fish Checklist in Pergau Reservoir and its Catchment Area, Kelantan

An ichthyological survey was carried out at Pergau Reservoir and its catchment area during the scientific expedition of Pergau Reservoir that was held on 28th October to 2nd November 2019. The objective of this study is to determine fish checklist present at the reservoir and its catchment area. Various sampling gears were used to maximize fish collections such as eletrofishing, cast nets, gill-nets, rod fishing and scoop nets. A total of 20 fish species from 10 families were recorded during the study. Two fish species listed as ‘Data Deficient’ category, Tor tambra (Malayan Mahseer) and Betta kuehnei (Betta) were also recorded, indicating proper management plan should be carried out to preserve important species from being overexploited. The present study also added new recorded fish checklist, Macrognathus maculatus to the total fish checklist. So, the total of combined fish checklist from past to present studies were 49 fish species including four non-native species. This information is helpful for the development of management plan of Sultan Ismail Petra Ecosystem Protection Park that is currently in the process of the gazzetment.

The diversity of fresh water snail fauna in Kiri dam, Adamawa State, North Eastern Nigeria

Freshwater Snails are crucial in assessing the ecological status of water bodies, besides their economic, public and veterinary health importance. Hence, the need to study the occurrence, and diversity of freshwater snails in Kiri dam where there is paucity of such information becomes imperative. Accordingly, this study was carried out between December, 2016 and July, 2018. Snails were searched for in the five contact sites identified using long handle metal scoop nets in accordance with standard procedure. Snails recovered were examined for natural infections. Eleven (11) different fresh water snail species were encountered including Bulinus globosus, Bulinus truncatus, Biomphalaria pfeifferi, Lymnaea natalensis, Lanistes ovum, Lanistes varicus, Pila ovata, Melanoides maculata, Melanoides tuberculata, Bellamya unicolor and Gabiella tchadiensis of the eleven different snail species examined, only Bulinus globosus Bulinus truncatus and Biomphalaria pfeifferi shed schistosome cercariae. The other 8 species did not have any natural infections. The study revealed that Kiri Dam harbours diverse species of fresh water snails including those of public health importance. The presence of naturally infected snails indicates that the people engaging in various activities in the dam, are predisposed to infections harboured by these snails.

A molecular approach to identifying the relationship between resource use and availability in Eurasian otters (Lutra lutra)

In South Korea, the Eurasian otter (Lutra lutra (Linnaeus, 1758)), a semi-aquatic carnivore, is found mainly in lower order streams that tend to have a low abundance of preferred prey fish species. To investigate the relationship between resource use and availability, we used DNA barcoding to identify otter diet items in 24 otter spraints (faeces) from 16 sites along the Nakdong River basin from 4 to 6 June 2014. At these sites fish availability was assessed using scoop nets and casting nets. Fish formed the bulk of otter diet, which included also frogs, mammals, and reptiles. By DNA barcoding (success rate: 72.38%), we identified 79 prey items from 105 bone remains. The diet comprised mostly fish, but frogs, mammals, and reptiles were also identified. The fish fauna and otter diet composition differed significantly. Across the study sites, members of the Cyprinidae dominated in netted samples, but occurred less frequently in otter diet. Because most Cyprinidae are fast swimmers, otters also fed on benthic fishes and frogs, suggesting limited foraging flexibility in otters and specialization on more slowly moving prey.

Juvenile and small fish diversity in mangroves of different root types in the Labuhan Coastal Area, Bangkalan, Indonesia

Abstract. Muzaki FK, Saptarini D, Ibadah AC. 2019. Juvenile and small fish diversity in mangroves of different root types in the Labuhan Coastal Area, Bangkalan, Indonesia. Biodiversitas 20: 1537-1543. The complexities of mangrove root types are well known to have effect on communities of fish including larval, juvenile and adult stages. This study aimed to access the difference on species composition and diversity of juvenile and small fish from mangrove area of different root types, especially in mangroves of the coastal area of Sepulu, Bangkalan which is a mangrove protection area. The samples were collected from November 2016 to June 2017 using modified centipede nets and scoop nets. Four types of sampling locations were used. Areas with pneumatophores (S), stilt roots (R), a combination of both types (C) and areas without mangroves (T). At least 32 species from 16 families of juvenile and small fish were identified. Families of fish with highest number of species were Gobiidae with 13 species, followed by Ambassidae, Mugilidae, Eleotridae and Siganidae with 2 species each. Fish species with highest abundance in all sampling sites and periods were Oryzias javanicus (F. Adrianichthyidae, 22.039%), Ambassis kopsii (F. Ambassidae, 17.878%), Liza vaigiensis (F. Mugilidae, 9.613%), Am. buruensis (F. Ambassidae, 9.261%), Terapon jarbua (F. Terapontidae, 7.562%), L. subviridis (F. Mugilidae, 7.385%) and Pseudogobius javanicus (F. Gobiidae, 7.385%), respectively. Result of two-way Anova (p=0.05) suggest that area with stilt roots (R) which were dominated by mangrove Rhizophora have relatively higher abundance and species richness of juvenile and adult small fish. In addition, average Shannon-Weaner diversity index (H’) value in areas with stilt roots was 2.031 and highest compared to the other sampling sites.