Guilherme Pablo D B, Rosa Leonardo C
Rev Biol Trop. 2014 Mar;62(1):59-68.
The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.
缘边砂海星分布于新热带地区，在巴西海岸许多地方的虾拖网副渔获物中是一种数量极多且常见的物种。这导致其面临灭绝威胁，此外，其生物生态学方面也鲜为人知。因此，本研究的主要目的是分析巴西南部巴拉那州沿海栖息的缘边砂海星种群长度结构和摄食习性的季节变化。分析的标本于2008年2月（夏季）、4月（秋季）、6月（冬季）和10月（春季）从虾拖网副渔获物中采集。在实验室中，测量每个个体的长度，然后用分析天平称重。之后，对两个最常见长度类别的10个个体的胃内容物进行季节性分析。确定每个猎物类别的相对频率和丰度，然后合并为一个食物重要性指数。共采集到994只缘边砂海星，体长范围为7.0至56.2毫米，但大多数个体体长在20.1 - 25毫米类别。体长大于40毫米的个体仅在春季采集到，而在秋季和冬季发现了一些幼体（<10毫米）。个体总重量范围为0.1至15.3克，体重 - 体长关系显示为负异速生长（b<2.54）。关于其食物消耗，这种海星探索了11种食物，其中口足类动物和软体动物是最常见的食物。秋季记录到空腹频率较高。还观察到探索猎物和摄入食物的数量以及猎物组成的季节性差异。冬季 - 春季记录到的探索猎物类别和摄入食物数量高于夏季 - 秋季。猎物类别优势从腹足类动物（夏季和秋季）转变为口足类动物（冬季和春季）。腹足类动物在夏季和秋季作为主要猎物类别的重要性应予以仔细考虑，因为同时观察到空腹频率高和摄入食物数量少。观察到的摄食行为模式的季节性差异主要与猎物可获得性低和海星摄食率变化有关，并且可能反映在一些生物学特征上，例如栖息在巴西南部巴拉那州沿海海域的种群体型较小。
