Mariappan P, Balasundaram C, Schmitz B
Crustacean Aquaculture and Behaviour Unit (CRABU), Department of Animal Science, Bharathidasan University, Tiruchirapalli 620 024, India.
J Biosci. 2000 Sep;25(3):301-13. doi: 10.1007/BF02703939.
The structure, growth, differentiation and function of crustacean chelipeds are reviewed. In many decapod crustaceans growth of chelae is isometric with allometry level reaching unity till the puberty moult. Afterwards the same trend continues in females, while in males there is a marked spurt in the level of allometry accompanied by a sudden increase in the relative size of chelae. Subsequently they are differentiated morphologically into crusher and cutter making them heterochelous and sexually dimorphic. Of the two, the major chela is used during agonistic encounters while the minor is used for prey capture and grooming. Various biotic and abiotic factors exert a negative effect on cheliped growth. The dimorphic growth pattern of chelae can be adversely affected by factors such as parasitic infection and substrate conditions. Display patterns of chelipeds have an important role in agonistic and aggressive interactions. Of the five pairs of pereiopods, the chelae are versatile organs of offence and defence which also make them the most vulnerable for autotomy. Regeneration of the autotomized chelipeds imposes an additional energy demand called "regeneration load" on the incumbent, altering energy allocation for somatic and/or reproductive processes. Partial withdrawal of chelae leading to incomplete exuviation is reported for the first time in the laboratory and field in Macrobrachium species.
本文综述了甲壳类动物螯足的结构、生长、分化及功能。在许多十足目甲壳动物中，螯的生长与异速生长水平呈等比例关系，直至青春期蜕皮时异速生长水平达到1。此后，雌性继续保持相同趋势，而雄性的异速生长水平则出现显著激增，同时螯的相对大小突然增加。随后，它们在形态上分化为碾碎型和切割型，使其成为异型螯且具有性别二态性。在这两种螯中，较大的螯在争斗时使用，而较小的螯则用于捕获猎物和清理。各种生物和非生物因素都会对螯足的生长产生负面影响。螯的二态生长模式可能会受到寄生虫感染和底物条件等因素的不利影响。螯足的展示模式在争斗和攻击互动中具有重要作用。在五对步足中，螯足是多功能的攻防器官，这也使其成为最容易自切的部位。自切后螯足的再生会给个体带来额外的能量需求，即“再生负荷”，从而改变用于体细胞和/或生殖过程的能量分配。在实验室和野外首次报道了罗氏沼虾属物种中出现导致不完全蜕皮的螯足部分退缩现象。
