Larval biotopes of mosquitoes (Diptera: Culicidae) on the Berezinsky Biosphere Reserve (Belarus)

The purpose of the research is to study of larval biotopes of the family Culicidae Meigen, 1818 on the territory of the Berezinsky Biosphere Reserve.Materials and methods. Mosquito larvae collected on the Berezinsky Biosphere Reserve in 2016–2020. A total of 7772 mosquito larvae were collected in the course of 1467 counts. Mosquito larvae were collected in four types of natural reservoirs: permanent open (I); permanent shaded (II); temporary open (III) and temporary shaded (IV). The larvae were collected by dip net. The specimens were identifed using standard keys; in certain cases, the taxonomic collection of the Zoological Institute of the Russian Academy of Sciences (St. Petersburg) was used.Results and discussion.We found larvae of 22 mosquito species on the Berezinsky Biosphere Reserve. The genus Aedes Meigen, 1818 is the most abundant – 16 species (72,7%). The genus Anopheles Meigen, 1818 is represented by 2 species (9,2%), the genus Culiseta Felt, 1904 – 3 species (13,6%) and the genus Culex Linnaeus, 1758 – 1 species (4,5%). The largest number of species (18) is recorded in permanent and temporary open-type reservoirs, 17 – in temporary shaded reservoirs and the smallest number – 6 in permanent shaded reservoirs. Three species, Aedes vexans (Meigen, 1830), Ae. cantans (Meigen, 1818), and Ae. sticticus (Meigen, 1838) were found at all types of water bodies. The main larval breeding habitats are reservoirs of temporary origin with varying degrees of shading (88,0%). There are the highest abundance and mean average density of larvae. Thus, in temporary open water bodies, the abundance is 52,4% (with an average density of 197,0±45,7 sp./m2), and in temporary shaded water bodies, the abundance is 35,5% (with an average density of 287,2±162,1 sp./m2). For permanent reservoirs with varying degrees of shading, a low abundance and an average density of larvae are noted. Thus, in permanent open water bodies, the abundance is 9,6% (with an average density of 27,0±7,7 sp./m2), and in permanent shaded water bodies, the abundance is 2,5% (with an average density of 19,4±6,0 sp./m2). In permanent open water bodies, the greatest species diversity is noted, which is confrmed by the values of the indices (Нʹ = 3,06; D Mg = 2,57 and DSm = 0,16)

PENDUGAAN STOK IKAN DI SUNGAI KAPUAS, KALIMANTAN BARAT

Sungai Kapuas, Kalimantan Barat mempunyai tipe ekosistem yang kompleks dan keanekaragaman jenis ikan tinggi. Sungai Kapuas ini sudah mendapat tekanan dari luar terutama dari pertanian, perkebunan, dan pertambangan. Akibatnya, beberapa jenis ikannya sudah mulai langka antara lain ringo (Datniodes quadrifsciatus), siluk (Scleropags formosus), belantau (Macrochirichthys macrochirus), dan kapas (Rohteichthys microlepis). Suatu kajian stok ikan dengan menggunakan metode akustik dilakukan pada bulan Juli dan Desember 2006 di Sungai Kapuas. Lokasi yang diambil adalah ruas Sungai Kapuas dari Pontianak ke hilir sampai Muara Jungkat, ruas Sungai Kapuas dan ruas anak sungainya sekitar Tayan, ruas anak sungai perairan banjiran di kawasan Sentarum dan satu buah danau sungai mati yaitu Danau Empangau. Untuk mengetahui komposisi jenis ikan, pengambilan contoh ikan dilakukan dan hasil tangkapan dicatat oleh enumerator. Stok ikan di hilir antara Pontianak dan Muara Jungkat adalah 1.847 ind./Ha, di Tayan pada sungai Kapuas dan anak sungainya masing-masing adalah 157 dan 403 ind./Ha, di kawasan Sentarum berkisar 1.087 - 1.634 ind./Ha, dan di Danau Empangau adalah 5.708 ind./Ha. Jenis ikan yang mendominansi di perairan antara Pontianak ke Muara Jungkat yaitu sengarat (Kryptopterus trichopterus) dan baung (Mystus nemurus), di Tayan yaitu kotol mulut (Amblyrhycnchichthys truncatus) dan kelabau (Osteochilus melanopleura), di kawasan Sentarum yaitu bauk (Labiobabrus spp.), sepat (Trichogaster trichopterus), dan toman (Channa micropeltes), serta di Danau Empangau yaitu entukan (Thynnichthys thynnoides), umpan (Puntius waandersii), dan biawan (Helostoma temminckii).  Kapuas River, West Kalimantan has various ecosystem types and high fish biodiversity. This river has been pressured by other sectors such as agriculture, plantation, and mining. Some of fish species such as ringo (Datniodes quadrifsciatus), siluk (Scleropags formosus), belantau (Macrochirichthys macrochirus), and kapas (Rohteichthys microlepis) endanger. A study on fish stock assessment using accoustic methods was done on July and December 2006 in Kapuas River. The locations selected in this study were down stream from Pontianak to Muara Jungkat, segment of Kapuas River and its tributary around Tayan area, in segment of Sentarum floodplains (Empangau oxbow lake). Average fish stock in downstream segment was 1,847 ind./Ha, around Tayan in main river and its tributary was 157 ind./Ha and 403, respectively, in Sentarum ranged 1,087 - 1,634 ind./Ha and in Empangau Lake was 5,708 ind./Ha. Fish species dominance from Pontianak to Muara Jungkat was sengarat (Kryptopterus sp.) and baung (Mystus nemurus), in Tayan was kotol mulut (Amblyrhycnchichthys truncatus) and kelabau (Osteochilusmelanopleura), in Sentarum was bauk (Labiobabrus spp.), sepat (Trichogaster trichopterus), and toman (Channa micropeltes), and in Empangau Lake were entukan (Thinnichthys thynnoides), umpan (Puntius waandersii), and biawan (Helostoma temminckii)