博斯腾湖河鲈早期发育阶段关键生境特征的调查

为研究博斯腾湖河鲈(Perca fluviatilis)早期发育阶段繁殖水域的生境特征,于2014年3-4月对白海子及相邻水域的水体理化因子、鱼类组成、高等水生植物、底栖动物群落结构进行了调查。结果表明:河鲈在3月进入繁殖期,4月结束;虽然鱼类种类组成相似,但繁殖期白海子河鲈优势度明显高于相邻水域,白海子是河鲈主要繁殖水域;繁殖期水温8~17℃,繁殖盛期水温11~14℃,繁殖水深(1.4±0.2)m,DO(6.8±0.1)mg/L,pH 7.9,电导率(46.5±0.4)ms/m,矿化度(351.7±2.4)mg/L,总磷(0.02±0.00)mg/L,总氮(1.18±0.07)mg/L,氨氮(0.98±0.00)mg/L,叶绿素a(0.32±0.01)μg/L;白海子高等水生植物由臭轮藻(Chara foetida)单一群落构成,覆盖率约88.1%,密度和生物量分别为6154.7 ind/m~2和8346.4 g/m~2,相邻水域则由金鱼藻(Ceratophyllum demersum)、狐尾藻(Myriophyllum)、竹叶眼子菜(Potamogeton malaimus)和白睡莲(Nymphaea alba Linn)等群落构成,覆盖率约66.7%,密度和生物量分别为171.7 ind/m2和2 097.8 g/m~2。白海子采集底栖动物5种,为羽摇蚊(Chironomus plumosus Larve)幼虫、小斑蜻(Libellula quadrimaculata)幼虫、长叶瘦蟌(Ischnura elegans)幼虫、耳萝卜螺(Radix auricularia)和扁旋螺(Gyraulus comperssus),总密度和总生物量分别为23 150 ind/m~2、76.663 g/m~2;其中,栖于底泥的底栖动物仅羽摇蚊幼虫,密度和生物量分别为(736.0±117.2)ind/m~2、(7.478±1.320)g/m~2,附着于臭轮藻茎叶表面的底栖动物有羽摇蚊幼虫、小斑蜻幼虫、长叶瘦蟌幼虫、耳萝卜螺和扁旋螺,密度和生物量分别为22 414 ind/m~2、69.185 g/m~2。相邻水域底泥及水生植物茎叶表面均未采集到底栖动物。水温、透明度及水深是影响河鲈繁殖水域分布的主要水环境因素,而附卵基质则是主要的生物因素;河鲈选择臭轮藻作为附卵基质有着明显的倾向性,其在避害、栖息、摄食等方面发挥重要功能。

Survey on habitat characteristics of key perch in early developmental stage of Perca fluviatilis in Bositeng Lake

To find out breeding area of Perca fluviatilis and master habitat characteristics of its early developmental stage, physical and chemical factor of water, fish composition, and community structure of aquatic higher plant and benthic ani-mal in Baihaizi and adjacent waters were investigated during March to April, 2014.The Results showed that P.fluviatilis started breeding in March and ended in April.Although fish composition was similar, Baihaizi had a higher degree of domi-nance than adjacent waters in breeding season; Baihaizi was the principal breeding site of P.fluviatilis.Water temperature was at 8 -17 ℃ during breeding stage, and was at 11 ~14 ℃ during peak period.Water depth of breeding area was (1.4 ±0.2) m, DO was (6.8 ±0.1) mg/L, pH was 7.9, conductivity was (46.5 ±0.4) ms/m, salinity was 351.7 ± 2.4 mg/L, total phosphorus was (0.02 ±0.00) mg/L, total nitrogen was (1.18 ±0.07) mg/L, ammonia nitrogen was (0.98 ±0.00) mg/L, and chlorophyll a was (0.32 ±0.01) μg/L.The single community of Chara foetida constituted the aquatic higher plant of Baihaizi, its fraction of coverage was about 88.1%, density was 6 154.7 ind/m2 , and biomass was 8 346.4 g/m2.The plants of adjacent waters were composed of Ceratophyllum demersum, Myriophyllum, Potamogeton malaimus and Nymphaea alba Linn communities, with coverage rate of 66.7%, density of 171.7 ind/m2 , and biomass of 2 097.8 g/m2.Five benthic animals were collected in Baihaizi, it was Chironomus plumosus Larve, Libellula quadrimacula-ta, Ischnura elegans, Radix auricularia and Gyraulus comperssu, total density and biomass was 23 150 ind/m2 and 76.663 g/m2 , respectively.Chironomus plumosus larve inhabited in bottom sediment, its density and biomass was (736.0 ±117.2)ind/m2 and (7.478 ±1.320) g/m2; all five species inhabited in stem leaf surface of C.foetida, its density and biomass was 22 414 ind/m2 and 69.185 g/m2.No benthic animals were collected from bottom sediment and stem leaf sur-face in adjacent waters.Water temperature, transparency and depth were main water environment factors impacting the dis-tribution of breeding area, and adhesive material was the principal biological factor.P.fluviatilis showed an obvious tend-ency to choose C.foetida as adhesive material; the materials played an important role in avoiding disadvantages, inhabiting and feeding.