Alien Freshwater Fish Cultured in Malaysia: Economic Development or Native Fish Species Extinctions

Human activities to increase economic productivity and food supplies have contributed to the introduction of alien fish into freshwater ecosystems. The introduction of alien fishes for aquaculture, recreational fisheries, stocking enhancement, biological control and aquarium fish industry has also led to the establishment of alien species in local aquatic habitats. More than 24 species of alien fishes, mainly for culture have been introduced into Malaysian fresh waters for the past 40 years. It is likely that alien species in Malaysia have positive impacts on various economies in the country. Despite some arguably positive effects on biodiversity at the local scale, an overwhelming amount of evidence indicates the profoundly negative effects of alien species introduction on genetic diversity as a whole. Presently, there are neither documented information nor specific research programs in Malaysia about the roles and contributions of alien fish on aquaculture development as well as the impacts on other native fish fauna. Therefore, the documentation of the influence and the effects of alien fish species on aquaculture development in Malaysia is vital. If alien species abundance increases in the future, it will be easier to identify changes, particularly on native fish fauna and other natural resource related to the increased abundance of alien fish or other causes

Survey of freshwater fish fauna in the upper rivers of Crocker range National Park Sabah, Malaysia

The fish fauna distribution in six rivers in the Crocker Range National Park was examined. All the six rivers surveyed were generally shallow, fast flowing with clear water and rocky and sandy substrate. At the time of survey, all rivers gave excellent water quality data. A total of 17 fish species belonging to four families were sampled. The gastromyzontids represented the major species in all the rivers surveyed, comprising 59.5% of the total number of fish caught. Commercially valuable fish such as the Tor species was also found in the rivers studied

A Survey of Freshwater Fish Fauna in the Upper Rivers of Crocker Range National Park Sabah, Malaysia

The fish fauna distribution in six rivers in the Crocker Range National Park was examined. All the six rivers surveyed were generally shallow, fast flowing with clear water and rocky and sandy substrate. At the time of survey, all rivers gave excellent water quality data. A total of 17 fish species belonging to four families were sampled. The gastromyzontids represented the major species in all the rivers surveyed, comprising 59.5% of the total number of fish caught. Commercially valuable fish such as the Tor species was also found in the rivers studied

KEANEKARAGAMAN SPESIES CACING PENGGEREK KAYU LAUT DARI HUTAN MANGROVE SETAPOK BESAR KOTA SINGKAWANG KALIMANTAN BARAT

Hutan mangrove Setapok Besar terletak di Kota Singkawang Provinsi Kalimantan Barat. Daerah ini secara langsung berbatasan dengan Laut Natuna dan menjadi areal penangkapan ikan. Nelayan membangun sero atau tambak ikan dengan jarak 4 mil dari pantai sebagai tempat untuk menangkap ikan. Tambak dibuat dari kayu dan kayu selalu diserang cacing penggerek kayu laut setelah 6 bulan dan mengalami kerusakan. Penelitian bertujuan untuk menginventarisasi keanekaragaman spesies cacing penggerek kayu laut dari hutan mangrove Setapok Besar Kota Singkawang. Metode penelitian dilakukan dengan survey eksploratif di hutan mangrove dan areal sero atau tambak ikan. Kayu yang diserang cacing penggerek kayu laut dikumpulkan kemudian cacing dikeluarkan dari kayu dan dimasukkan ke dalam botol yang berisi alkohol 70%. Identifikasi jenis dilakukan di Laboratorium Teknologi Kayu Fakultas Kehutanan Universitas Tanjungpura. Faktor lingkungan yang meliputi kualitas air dan tanah dievaluasi. Hasil penelitian menunjukkan keaneragaman spesies cacing penggerek kayu laut yang berasal dari kayu yang digunakan di sero atau tambak ikan lebih tinggi daripada di kayu yang berasal dari hutan mangrove. Spesies cacing penggerek kayu laut yang ditemukan berjumlah 15 spesies yang berasal dari 2 famili, yaitu famili Teredinidae dan Pholadidae. Cacing penggerek kayu laut yang ditemukandi kayu dari sero atau tambak ikan meliputi Neoteredo reynes, Teredo pocalifer, Teredo utriculus, Teredo siamens, Teredo navalis, Teredo batiliformis, Teredo dagmarae, Teredo dallii, Martesia striata, Bankia setacea, Bankia minimadan Petricola pholadiformis.Spesies cacing penggerek kayu laut yang ditemukan di kayu dari hutan mangrove meliputi Bankia caribbea, Bankia fimbriulata, Bankia minima, Martesiastriatadan Teredo navalis. Nilai keanekaragaman jenis cacing penggerek kayu laut adalah 2,6699 yang menunjukkan indeks keanekaragaman jenis tinggi. Nilai indeks dominansi sebesar 0,07156 yang menyatakan terdapat jenis cacing penggerek kayu laut yang dominan.Nilai kelimpahan jenis sebesar 0,9859 yang menunjukkan indeks kelimpahan jenis tinggi.Nilai indeks kekayaan jenis sebesar 2,00678 dan termasuk dalam kategori kekayaan jenis sedang. Faktor lingkungan sangat mendukung untuk perkembangan cacing penggerek kayu laut. Nilai rata-rata pH tanah sebesar 8,16; kandungan C-organik 2,76%; kadar pasir 12,30%; kadar liat 37,19%; kadar debu 50,51%. Nilai rata-rata pH air 7,92; salinitas 7,86%; BOD 9,54 mg/l; COD 528,86 mg/l dan DO 4,68 mg/l. Distribusi cacing penggerek kayu laut tersebar dari hutan mangrove sampai ke sero tambak ikan. Hal ini menunjukkan habitat hutan mangrove Setapok Besar cocok untuk pengembangan cacing penggerek kayu laut dan memberikan prospek pemanfaatan yang baik sebagai sumber pangan

First record of marine wood borer (Mollusca: Teredinidae) Dicyathifer mannii Wright (1866) in Sabah, Malaysia, with detailed measurement metrics

The present study describes the new record of Dicyathifer mannii under the family Teredinidae Rafinesque, 1815. Sampling was conducted in the mangrove area of Kuala Penyu and sample was collected from dead wood debris. The pallets of Dicyathifer is half-conical in shape and 8mm in length. The cone measured 3.9mm in length and 3.6mm in width. The cavity is 1.2mm deep; the curve of the opening on the cone is about 98% of the depth of the cone. Inside the cone cavity, from the center, a ridge with rib-like feature runs down the length of the cavity. Only one species of Dicyathifer is recorded and the present species is the first new record described in Malaysia with some additional measurement metrics for future taxonomic identification purposes

Body Indices and Population Dynamics of Setipinna breviceps (Cantor, 1849) from Batang Lassa Estuary, Sarawak, Malaysia

The Setipinna breviceps is a commercially important and highly esteemed food fish. This species has scant of scientific formation particularly on population parameters like growth, mortality and recruitment. The present study aimed to estimate the body indices and population parameters of Setipinna breviceps of Batang Lassa Estuary (BLE). Samples were collected between April 2019 and September 2020. A local made bag net known as Gnian (mesh size 1.25 to 4.00 cm) was used for sampling the fish. A total of 287 qualified specimens were used for this study. The length and weight of individual fish was measured to the nearest 0.1 cm and 0.01 g, respectively. The length ranged from 5.50 to 24.00 cm and growth coefficient (b) was 2.563 (R 2 = 0.87) which clearly indicated a negative allometric growth. About 50% of individuals showed flat or slender body (Kn1) while 2.44% of fishes measured an ideal shape (Kn = 1). The parameters of growth L∞, K and ϕ’ were estimated at 24.15 cm, 0.23 yr-2 and 2.13, respectively. The estimated natural mortality and fishing mortality were 0.74 and 0.29 yr-2 , respectively and exploitation rate was 0.28. The recruitment pattern during the study was observed at two possible unequal peaks. The present study concluded that the anchovy was under exploited (E<0.5) as demonstrated by the under-sized fishes caught with small mesh size net. However, considering the minimum lengths and length at first catch, the BLE could be a productive nursery ground for S. breviceps. Therefore, management actions are required to avoid juvenile catches

Biometric indices and population parameters of three polynemid fishes from Batang Lassa Estuary of East Malaysia

The length-weight relationships (LWRs), condition factor (Kn), growth, mortality and exploitation status of three polynemid fishes, i.e., Filimanus xanthonema (Valenciennes, 1831), Polynemus melanochir (Valenciennes, 1831) and Polynemus paradiseus (Linnaeus, 1758) from Batang Lassa River estuary were estimated. Fish samples were caught during April 2019 to September 2020 using the ESBN (locally called Gnian) having 1.25 to 4.00 cm mesh size. The total length (TL) and body weight of each individual fish was measured to the nearest 0.1 cm and 0.01 g respectively. The growth coefficients (b) for F. xanthonema, P. melanochir and P. paradiseus, were 2.880, 2.717 and 2.724 with the R2 values 0.956, 0.972 and 0.936 respectively. Estimated growth coefficients indicated a negative allometric growth pattern for all three threadfin fishes. To date, information regarding length-weight relationships for F. xanthonema and P. melanochir is insufficient whereas the information is available for P. paradiseus. About 40–48% of fishes exhibited flat or thin body shape (Kn 1) and only 1–3% of fishes showed proportional body shape (Kn = 1). The growth parameters L∞, K and ϕ’ were estimated at 15.75 cm, 0.95 yr−1 and 2.37 for F. xanthonema; 27.61 cm 0.87 yr−1 and 2.82 for P. melanochir; and 27.30 cm, 0.58 yr−1 and 2.64 for P. paradiseus; respectively. The estimated natural mortality (M) included 2.10, 1.69 and 1.30 yr−1 ; the fishing mortality (F) 0.57, 0.67 and 0.60 yr−1 ; and exploitation ratio (E) 0.21, 0.28 and 0.31 for F. xanthonema, P. melanochir and P. paradiseus respectively. The study concluded that the stocks are still under exploitation (E < 0.5) condition. However, the studied Batang Lassa estuary could be a potential nursery ground considering the minimum lengths of 5.0, 3.8 and 4.0 cm for F. xanthonema, P. melanochir and P. paradiseus respectively. Therefore, management initiatives are needed to escape juvenile catches

Phylogenetic relationships among Mahseers (Cyprindae) in Malaysia inferred from Sequencing of a cytochrome c oxidase I (COI) Mitochondrial DNA (mtDNA) segment

The present study examines the phylogenetic relationships among Tor douronensis, T. tambra, T. tambroides of the genus Tor and Neolissochilus stracheyi representing the genus Neolissochilus, by using the partial sequencing of the mitochondrial DNA cytochrome c oxidase I (COD gene. Samples were collected from various rivers throughout Sarawak, Sabah and Peninsular Malaysia. The phylogenetic analysis obtained by using the Neighbour Joining (NI) and Maximum Parsimony (MP) procedures supported the monophyletic status among the three mahseers, except between T. tambroides and T. tambra. The high genetic divergence separating T. douronensis and T. tambroides or T. tambra confirmed their status as distinct species. Likewise, the high genetic divergence separating the N. stracheyi lineage from the Tor lineages (7.3-L1.0%) also supported its recent reclassification from the genus Tor rnto the genus Neolissochilus. The identical haplotypes found between all the T. tambra sequences with most of the T. tambroides sequences indicated a very close genetic relationship between them. Similarly, the close genetic relationships (0-0.a%) found between T. tambroides samples from Peninsular Malaysia (kelah fish) and those from Sarawak (empurau fish) supported their taxonomic status as belonging to the same species. Phylogenetic analysis also revealed that the T. douronenszs mtDNA consisted of three highly distinct lineages (Sabah, northern and southern Sarawak), consistent with their geographical locations. However, our phylogenetic analysis did not find any T. douronensls group to be genetically more similar to T. tambroides (6.3-9.2%). Overall, the present study managed to provide useful insights into the phylogeny and taxonomy of the mahseers in Malaysi

Concentrations of Cadmium, Copper, and Zinc in Macrobrachium rosenbergii (Giant Freshwater Prawn) from Natural Environment

This study analyzed the levels of cadmium (Cd), copper (Cu), and zinc (Zn) by the flame atomic absorption spectrophotometer (FAAS), in the muscle tissues, exoskeletons, and gills from freshwater prawn (Macrobrachium rosenbergii) (n = 20) harvested from natural habitat in Kerang River, Malaysia on 25th November 2015. Significant increase of the metals level in muscle tissue and gill (r > 0.70, p < 0.05) were observed with increase in length except for Cu in gills. No relationship was found between metals level in exoskeleton and length. The concentrations of Cd, Cu and Zn were significantly higher (p < 0.05) in males (muscle tissues and exoskeleton) except for Cd in exoskeleton. In gills, only Cu was significantly higher (p < 0.05) in female than male. All samples contained metals below the permissible limit for human consumption (i.e., Cd < 2.00 mg/kg; Cu < 30.00 mg/kg; Zn < 150 mg/kg). Annual metals monitoring in prawn and environmental samples is recommended to evaluate changes of metals bioaccumulation and cycling in the system, which is useful for resources management. © 2018 Springer Science+Business Media, LLC, part of Springer Natur