Microcotyle stenotomi

Microcotyle stenotomi was first described by Goto in 1899.^[1] The drawings given in the original account lack detail and clarity.^[2] Microcotyle stenotomi was subsequently redescribed by Linton in 1940 ^[3] who added only a few measurements without improving the original drawings of Goto.^[2] McMahon noted the lack of some quantitative features in the original account and the necessity of a redescription of the species.^[2]

Microcotyle stenotomi has the general morphology of all species of Microcotyle, with a symmetrical, narrow body, comprising an anterior part which contains most organs and a posterior part called the haptor. The haptor is symmetrical, occupies about one-third of body length and bears 46 pairs of minute clamps, arranged as two rows, one on each side. The clamps of the haptor attach the animal to the gill of the fish. There are also two small buccal suckers at the anterior extremity. The digestive organs include an anterior, terminal mouth, a muscular pharynx, a short oesophagus and a posterior intestine with two lateral branches provided with numerous secondary branches on the outer side and very short diverticula on the inner side. Each adult contains male and female reproductive organs. The reproductive organs include an anterior spacious genital atrium opening at level of oesophagus, armed with numerous very small and slightly recurved spines, a medio-dorsal vagina opening midway between the anterior end of the body and the level of the ovary, a single incompletely S-shaped ovary consisting of a convoluted tube, a uterus opening through the genital pore, vitellarium giving off ducts which unite in a Y-shaped reservoir in the midline behind the ovary, an oviduct at the tip of the Y-shaped vitelline reservoir and several testes which are posterior to the ovary and present in a great group in the midpart of the body.^[1]

The specific name stenotomi refers to the generic name of the host species Stenotomus chrysops.^[1]