Population Dynamics, Life History, and Production of Cyathura Carinata (Krøyer) (Isopoda: Anthuridae) in the Mondego Estuary, Portugal
Population Dynamics, Life History, and Production of Cyathura Carinata (Krøyer) (Isopoda: Anthuridae) in the Mondego Estuary, Portugal
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葡萄牙蒙德戈河口 Cyathura Carinata (Krøyer)（等足目：Anthuridae）的种群动态、生活史和生产
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
S. Cruz
中科院分区：
文献类型：
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作者：
J. Marques;I. Martins;Carla Teles;S. Cruz
摘要 前期对蒙德戈河口底栖生物群落的研究表明，Cyathura carinata 种群数量时空稳定，全年生物量显着，是河口最丰富的物种之一。目前的工作是研究其种群动态和生命周期与物理化学因素的关系，并估计其在潮间带泥滩内的生产力。从1990年11月到1991年12月，每两周对Cyathura carinata进行一次采样。它在赤道带内表现出传染性的空间分布，其丰度随季节变化，从仲秋到晚春逐渐减少，从初夏到次年秋季再次增加。丰度似乎与浮现期呈负相关，与盐度和硝酸盐浓度呈正相关，而较高的温度和沉积物有机富集似乎对生物体的丰度产生负面影响。然而，丰度和环境因素之间的相关性不能被视为定义因果关系，因为环境因素也是相互关联的。推测先熟雌雄同体，雄性在三月到九月期间出现。性活动在早春开始，招募在整个夏季进行。产生了两组，一组在六月，另一组在八月。繁殖力与雌性体型显着相关。此外，较高的盐度和pH值有利于较高的繁殖力。尽管观察到生长率的季节性变化，但在动物的一生中生长是连续的。生长速度在冬季几乎停止，从冬末逐渐增加，在初夏和仲秋之间达到最大值，然后再次下降，直到第二年冬天。寿命粗略估计为18-22个月。据估计，雌性的性别分化发生在出生后 49-54 天，雄性则发生在 146-208 天。女性性成熟估计在 240-357 天（8-12 个月）内发生。 Cyathura carinata 是蒙德戈河口的半年生物种，雌性重复繁殖，生命周期单化。生长产量（P）和淘汰产量（E）估计分别为5.6-9.9和11.8-22.3 g·m―2·year―1无灰干重。 P/B 和E/B 比率估计分别为1.65-2.03 和3.74-4.37。尽管在繁殖期方面存在一些差异，但在欧洲海岸研究的所有 C. carinata 种群都显示出单性的生命周期。由于种群稳定和生命周期特征，该物种似乎是欧洲河口比较生态生理学和生态毒理学研究的理想选择。
ABSTRACT Previous studies of the benthic community in the Mondego estuary revealed that Cyathura carinata has spatially and temporally stable populations, has significant biomass throughout the year, and is one of the most abundant species in the estuary. The present work was carried out to study its population dynamics and life cycle in relation to physicochemical factors, and to estimate its productivity within intertidal mud flats. Cyathura carinata was sampled every two weeks from November 1990 to December 1991. It exhibited a contagious spatial distribution within the eulittoral zone, and its abundance changed seasonally, decreasing gradually from midfall to late spring, and increasing again from early summer to the following fall. Abundance appeared to be inversely related to emersion periods, and positively correlated with salinity and nitrate concentrations, while higher temperature and sediment organic enrichment appeared to have a negative effect on the abundance of organisms. Nevertheless, the correlations between abundance and environmental factors could not be considered as defining cause-andeffect, since environmental factors were also intercorrelated. Protogynous hermaphroditism was hypothesized, with males being present from March to September. Sexual activity began in early spring and recruitment took place through the summer. Two cohorts were produced, one in June and a second in August. Fecundity was significantly correlated with female size. In addition, higher salinities and pH favored higher fecundity. Although seasonal variations in growth rates were observed, growth was continuous through the life of the animal. Growth rates practically ceased during the winter, increased gradually from late winter to a maximum between early summer and midfall, and decreased again until the following winter. Life span was roughly estimated at 18-22 months. Sexual differentiation was estimated to occur within a period of 49-54 days from birth, for females, and 146-208 days for males. Sexual maturation in females was estimated to occur in 240-357 days (8-12 months). Cyathura carinata is a semiannual species in the Mondego estuary, with iteroparous females and an univoltine life cycle. Growth production (P) and elimination production (E) were estimated as, respectively, 5.6-9.9 and 11.8-22.3 g·m―2· year―1 ash-free dry weight. P/B and E/B ratios were estimated, respectively, as 1.65-2.03 and 3.74-4.37. Despite several differences with regard to the reproductive period, all populations of C. carinata studied along the European coasts show univoltine life cycles. Due to stable populations and life cycle characteristics, this species appears ideal for comparative ecophysiological and ecotoxicological studies in European estuaries.