Microscopic morphology of the antennule and antenna of the marine isopod Cirolana harfordi

ABSTRACT

The use of scanning electron microscopy on the cuticle outgrowths called setae (that contain sensilla) in crustaceans is useful for, understanding how crustacean species sense their environment and for taxonomic studies. So far, most of the setal morphology studies have been performed on decapod crustaceans such as lobsters and shrimps and there has been a comparative lack of such research on marine isopods, from which terrestrial isopods such as woodlice or slaters have evolved. In the current study, electron microscopy was used to study the antennal setae of the marine isopod Cirolana harfordi using magnification powers of up to 40, 000. C. harfordi displayed a number of setal types including setae that had a sub-terminal pore that contained a cupule-shaped structure and plumose setae which are pennate in structure and have two rows of setules along the setal shaft in a fashion analogous to a palm leaf. These plumose setae may be useful to the animal in detecting water currents. Differences in the structure and placement of setae on the antennae of C. harfordi as compared to two other marine isopods, Bathynomus pelor and Natatolana borealis (that have had a comprehensive study of antennae setal morphology performed on them in previous studies) indicate that scanning electron microscopy of isopod setae may be useful in taxonomic studies of isopods.     

厦门港海区两种常见纺缍水蚤(Acartia)形态特征的比较研究

研究了厦门港自然海区和实验室多世代培养的刺尾纺缍水蚤和太平洋纺缍水蚤的形态、季节分布以及温度对形态的影响等问题。结果表明:过去作为这两个种的订种主要依据之一——第五胸肢上的形态没有种间差异;订种的另一依据——第一触角上的差异,也仅表现在雌性第五期桡足幼体和成体上,而且有很多中间过渡形态;同一形态的亲代其子代成体也有多种形态。文中就导致这两种纺缍水蚤形态变异的可能原因以及不同形态间的生理差异进行了讨论。