Geets A, Coene H, Ollevier F
Laboratory for Ecology and Aquaculture, Catholic University Leuven, Belgium.
Parasitology. 1997 Jul;115 ( Pt 1):69-79. doi: 10.1017/s0031182097001054.
Different populations of the whitespotted rabbitfish, Siganus sutor, were examined for ectoparasites: adults from the Mombasa area (sampled in December 1990) and different age classes (adult, subadult and juveniles) from Gazi Bay (sampled in December 1992 and August 1993). The most common gill parasites were: the monogeneans Pseudohaliotrema sp., Tetrancistrum sigani and Microcotyle mouwoi, the copepods Hatschekia sp., Pseudolepeophtheirus sp. and juvenile Caligidae, and prazina larvae of the isopod Gnathia sp. Adult siganids had a higher parasite load than subadults. Juvenile rabbitfish did not harbour any gill parasites. Temporal differences in the parasite load of subadult rabbitfish were observed for M. mouwoi (highest in the December samples) and for juvenile Caligidae (highest in August). The microhabitat of the 5 most common gill parasites was species specific. Most parasite species showed distinct site preferences with respect to both gill arches and gill sectors, within the gill arches. Niche breadth of the different gill parasite species was independent of the abundance of any of the other species present. However, niche breadths of M. mouwoi, Tetrancistrum sp. and Hatschekia sp. increased with their own abundance. This suggests that interspecific competition for space is low and that intraspecific factors could play an important role in the microhabitat choice of these gill parasites. The hypothesis that niche restriction leads to higher intraspecific contact and an enhancement of chances to mate was tested on 2 monogenean species, Pseudohaliotrema sp. and Tetrancistrum sigani. Their highly aggregated distribution over the gill filaments, leading to increased intraspecific contact, is consistent with the hypothesis.
对白点兔鱼（Siganus sutor）的不同群体进行了体外寄生虫检查：来自蒙巴萨地区的成鱼（1990年12月采样）以及来自加齐湾的不同年龄组（成鱼、亚成鱼和幼鱼）（1992年12月和1993年8月采样）。最常见的鳃寄生虫有：单殖吸虫类的伪鲍氏吸虫属（Pseudohaliotrema sp.）、西氏四盘虫（Tetrancistrum sigani）和穆氏微杯虫（Microcotyle mouwoi），桡足类的哈氏鱼虱属（Hatschekia sp.）、伪鲈锚头鳋属（Pseudolepeophtheirus sp.）和幼体鱼虱科（Caligidae），以及等足类的颚虱属（Gnathia sp.）的普拉齐纳幼虫。成年兔鱼的寄生虫负荷高于亚成鱼。幼兔鱼未携带任何鳃寄生虫。观察到亚成鱼兔鱼的穆氏微杯虫（12月样本中最高）和幼体鱼虱科（8月最高）的寄生虫负荷存在时间差异。5种最常见鳃寄生虫的微生境具有物种特异性。大多数寄生虫物种在鳃弓内的鳃弓和鳃叶方面都表现出明显的位点偏好。不同鳃寄生虫物种的生态位宽度与任何其他共存物种的丰度无关。然而，穆氏微杯虫、四盘虫属（Tetrancistrum sp.）和哈氏鱼虱属的生态位宽度随其自身丰度增加。这表明种间空间竞争较低，种内因素可能在这些鳃寄生虫的微生境选择中起重要作用。在两种单殖吸虫类，伪鲍氏吸虫属和西氏四盘虫上检验了生态位限制导致更高种内接触和交配机会增加的假设。它们在鳃丝上高度聚集的分布导致种内接触增加，这与该假设一致。
