Abstract

Life cycle, population dynamics, growth, and annual production of Ecrobia maritima (Milaschewitsch, 1916) associated with the eelgrass Zostera noltei bed in the southern part of the Romanian Black Sea coast were investigated. Monthly quantitative random samples were taken from June to October 2015 and the collected snails of E. maritima were counted, measured, and weighted. The mudsnail E. maritima appears to be an annual species in the study area. The analysis of the size-frequency histograms indicated that recruitment took place over a brief period in June–July, after which the breeding population died. Growth of the overwintered cohort was slow during the cold season. A period of rapid growth of the new generation took place in June–July. The average life span was estimated at approximately 12–14 months. Under unfavourable conditions, individuals of E. maritima were observed to burrow into the sediment. Therefore, during the study period, the population of snails showed considerable variations of the above-ground density. The mean density of snails during the 5 months of study was 3204 ± 1419 ind. m⁻² and the mean biomass was 7.54 ± 3.06 g fresh weight (FW) m⁻². The cohort production over 5 months of study was estimated at 14.11 g FW m⁻². The obtained value for turnover (\({P \mathord{\left/ {\vphantom {P {\bar {B}}}} \right. \kern-0em} {\bar {B}}}\) = 1.87) is comparable to the estimates for other species of Hydrobiinae in similar habitats.

中文翻译：

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黑海罗马尼亚海岸的泥nail Ecrobia maritima（Milaschewitsch，1916）（Gastropoda：Prosobranchia）的生命周期，种群动态和产量

摘要

研究了与罗马尼亚黑海沿岸南部的鳗草Zostera noltei床相关的Ecrobia maritima（Milaschewitsch，1916）的生命周期，种群动态，生长和年产量。从2015年6月至2015年10月，每月采集一次定量样本，并对收集的海地蜗牛进行计数，测量和加权。泥nail E. maritima在研究区域似乎是一年生物种。对大小频率直方图的分析表明，招募是在6月至7月的短时间内进行的，此后繁殖种群死亡。在寒冷季节，越冬队列的生长缓慢。新生代快速成长的时期发生在6月至7月。平均寿命估计约为12-14个月。在不利的条件下，观察到海地大肠埃希菌的个体钻入沉积物中。因此，在研究期间，蜗牛种群的地面密度发生了很大变化。在研究的5个月中，蜗牛的平均密度为3204±1419 ind。m ^-2，平均生物量为7.54±3.06 g鲜重（FW）m ^-2。在研究的5个月中，该队列的产量估计为14.11 g FW m ^-2。获得的营业额值（\（{P \ mathord {\ left / {\ vphantom {P {\ bar {B}}}} \ right。\ kern-0em} {\ bar {B}}} \） = 1.87 ）可与类似栖息地中其他双歧杆菌的估计值相比。