Mesocoelium

Calhoun, Dana M. & Dronen, Norman O., 2012, A reevaluation of specimens of Mesocoelium monas (Platyhelminthes: Digenea: Mesocoeliidae) from the Natural History Museum, UK and the United States National Parasite Collection, USA, Zootaxa 3589, pp. 1-29 : 24

Mesocoelium cf pesteri— USNPC 0 89067.00

Host: Anolis sagrei (Dumeril & Bibron) (syn. Norops sagrei Dumeril & Bibron ), brown anole ( Squamata : Polychrotidae ).

Locality: Panama. (Native)

Description: Based on two specimens: Body 923 (806–1,040) by 585 (572–598); forebody 245 long, representing 27% of body length (n=1). Mouth subterminal; oral subspherical, 216 (208–224) by 246 (216–276); prepharynx absent; pharynx (could not be measured); esophagus (could not be measured); ceca short, terminating near anterior margin of ovary (cecal ends not visible, but ceca do not surpass ovary). Ventral sucker subspherical, situated in anterior 1/3 of body, 148 (135–161) by 153 (120–182); ratio of ventral sucker width to oral sucker width 1:1.7 (1:1.5–1:1.8).Genital pore prebifurcal, median. Uterus extensive, filling hindbody. Vitelline follicles distributed in lateral fields from level of upper margin of oral sucker to posterior margin of ovary. Eggs 34 by 23 (n=1). Excretory system not visible.

Remarks: In both specimens the forebody was contracted, pulling the oral sucker to within in a few micrometers of the ventral sucker. The poor quality of these two specimens precluded some measurements and other observations (e.g. cecal ends, only one egg measureable, cirrus sac, testes, ovary).

These specimens have ceca that do not surpass the ovary posteriorly and have a prebifurcal, median genital pore and are assigned to the pesteri body type, and cannot be M. monas . These specimens further differ from M. monas by having a narrower oral sucker (246 compared with 382), a narrower ventral sucker (120–182 compared with 344); ceca that terminate at anterior margin of ovary compared with ceca that terminate past posterior margin of ovary, and vitelline fields that terminate past the posterior margin of ovary compared with vitelline follicles that terminate well short of cecal ends.

The condition of these specimens precluded identification at the species level; however, egg size and general body morphology suggest that these specimens represent M. pesteri . It should be noted that the holotype of M. pesteri was in similar poor condition and extremely contracted.