Microcotyle archosargi has the general morphology of all species of
Microcotyle, with a flat body, comprising an anterior part which contains most organs and a posterior part called the
haptor. The haptor is symmetrical and bears a number of
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, and a posterior intestine with two lateral blind-ending branches. Each adult contains male and female reproductive organs. The reproductive organs include an anterior genital atrium, with spines, a dorsal
vagina, a single
ovary, and a number of
testes which are posterior to the ovary. In 2011, Kritsky and Bakenhaster provided supplementary observations for
M. archosargi based on examination of museum specimens and other specimens collected on
Archosargus probatocephalus from
Florida. The species was also redescribed by Mendoza-Franco
et al. in 2018, from
Archosargus rhomboidalis, including a drawing of the genital atrium. These authors also provided the first molecular data (
28S ribosomal RNA) for
Microcotyle archosargi. ==Etymology==