Biological characteristics on three demersal fish landed in Tegal, north coast of Central Java, Indonesia

Abstract

Abstract. Nugroho D, Patria MP, Supriatna J, Andrianto L. 2016. Biological characteristics on three demersal fish landed in Tegal, north coast of Central Java,. Java Sea has a potential marine biodiversity that has been harvested since years. Demersal fish resources is one of the targeted species by Danish seine fisheries operated in North coast of Java. To support on developing conservation and management measures, an observation on species composition, length frequencies and maturity stages were carried out during August 2014 to July 2015. Sampling took place in landing place of Tegalsari fishing port central Java. A total 129 fish species identified, among them 91 species were targeted as edible fish. Sampling on three dominant species i.e., Purple-spotted bigeye Priacanthus tayenus (Richardson, 1846) . Monthly average GSI of P. tayenus and S. taenioptera indicated that the highest index occurred during SE monsoon while U. sulphureus on NW monsoon. Maturity stage analysis indicated that estimated of length at first maturity (L m ) were at 12.9 cmFL (U. sulphureus), 16.8 cmFL (S. taenioptera) and 19.4 cmFL (P. tayenus). Size frequency distribution shows that most of the fish were caught at immature cohorts. The diversity or evenness indices of ichtyofauna is also described as descriptors of community structure and be complemented with information on biological characteristics of those dominant species.

Biological aspects of Longfin Mojarra (Pentaprion longimanus, Cantor 1849) in north coast of Central Java, Indonesia

“…Aglen et al (1981) informed that P. longimanus occurred in the waters of less than 60 m in Peninsular Malaysia. Nugroho et al (2016) indicate that the species were more abundant in the depth of more than 20 m in western part of the Java Sea.…”

“…This has been a growing concern in this fisheries for years. The persistence of high landing of juveniles and lower proportion of mature adults in Scottish seine fisheries suggests that large fish abundance was under pressure (Nugroho et al 2016). As the fish is a typically sedentary species it is predicted that the exploitation rates have a negative impact on current stock status, when the fishing mortality exceed half of the mature fish, the stock status fall below precautionary limits (Vasilakopoulos et al 2011) Gonadosomatic index (GSI) Gonadosomatic index (GSI) analysis indicated that monthly average slightly fluctuated except for May 2015 which give a high index.…”

“…Exploratory fishing in Natuna Sea showed that size distribution of Longfin Mojarra ranged from 4.0 to 20.0 cmFL (Wudianto and Sumiono 2008), while Sadhotomo and Sumiono (1983) indicates this species has fast growth rates. The contribution of annual landing of this species was relatively low (~5%) from the average total catch of demersal Scottish seine fleets in 2015 (Nugroho et al 2016). Despite available information on its abundance, little is known about the life history parameters of this edible species.…”

Naga people's (Tasikmalaya District, West Java, Indonesia) local knowledge of the variations and traditional management farm of village chickens

“…A total of 12,969 specimens were taken for length frequency distribution, among them, 2,038 fish specimens were collected for biological observations (688 Priacanthus tayenus, 587 Scolopsis taenioptera and 763 Upeneus sulphureus) belong to three different families of Priacanthidae, Nemipteridae and Mullidae. The biological characteristics of these species were previously described elsewhere (Nugroho et al 2016). Fish length was measured in mm, while weight measurement is in grams.…”

“…Among eight provincial coastal waters surrounding Java Sea, 93% of these species landed in the north coast of central Java. Previous studies on biological characteristics of dominant species in the north coast of Java have shown that landing is dominated by small size of fish and medium tropic level fisheries, therefore, the exploitation of the demersal fish species is suggested to be at risk (Nugroho et al 2016).…”