Mymarothecioides Soares and Domingues, 2019

Soares, Geusivam B., Magalhães, Keila X., Silva, Ana Carolina, Carneiro, Jânio S., Barbosa, Lucineia L., Costa, Nayna G. S. & Domingues, Marcus V., 2019, Monogenoids (Polyonchoinea, Dactylogyridae) from Hydrolycus armatus (Characiformes, Cynodontidae) with the description of a new species of Rhinoxenus and the proposal of a new genus from the Xingu River, Pará, Brazil, Zootaxa 4700 (2), pp. 229-245 : 233-234

Mymarothecioides Soares and Domingues n. gen.

Type species: Mymarothecioides xinguensis n. sp. from Hydrolycus armatus (Jardine & Schomburgk) .

Site: Gills.

Type locality: Volta Grande , Xingu River, municipality of Altamira, Pará State, Brazil (03°21’15,7’’S; 52°11’47,5’’W), collected on June 13, 2015 .

Other species: Mymarothecioides altamirensis n. sp.; Mymarothecioides ararai n. sp.; Mymarothecioides germanoi n. sp.; Mymarothecioides whittingtoni ( Kritsky, Boeger & Jégu, 1996) n. comb.

Etymology: The generic name indicates the similarity of this genus to Mymarothecium .

Zoobank Life Science Identifier: (LSID) for Mymarothecioides n. gen. is urn:lsid:zoobank.org:act:D3889C11-8D48-4F05-86D8-55BD6AAE6EBB

Diagnosis: Body divisible into cephalic region, trunk, peduncle, haptor. Tegument thin, smooth. Cephalic region with terminal ventral cephalic lobe; bilateral pairs of head organs opening subterminal to tip of cephalic lobes; cephalic glands lateral or postero-lateral to pharynx. Eyes absent; accessory chromatic granules present or absent. Mouth subterminal, midventral; pharynx muscular, glandular; esophagus short; two intestinal ceca, confluent posteriorly to gonads, lacking diverticula. Genital pore opening midventral, anterior to copulatory complex; genital atrium of soft tissue. Gonads tandem. One testis, dorsal to germarium; vas deferens looping left intestinal cecum; seminal vesicle sigmoid. One prostatic reservoir. Copulatory complex comprising articulated MCO, accessory piece; MCO sclerotized, tubular usually arcuate, small grooves at edges of distal opening present or absent; accessory piece sclerotized, distal end with hook-shaped process. Vagina single, dilated, nonsclerotized, opening on midventral or ventro-marginal surface near the midlength of trunk; vaginal vestibule muscular; vaginal canal non-sclerotized, sigmoid; seminal receptacle present, anterior to germarium. Vitellaria well developed, coextensive with ceca. Haptor globose or subhexagonal, with 14 hooks (8 marginal, 2 central, 4 dorsal); 2 pairs of anchors (1 ventral, 1 dorsal); 2 (1 ventral, 1 dorsal) haptoral bars. Ventral bar with anteromedial projection. Parasites of gills of characiform fishes.

Remarks: Mymarothecioides n. gen. resembles Mymarothecium Kritsky, Boeger & Jegú 1996 , mainly by including species with broad arcuate MCO, articulated with the accessory piece; the accessory piece with a subterminal hooked process; an anteromedial process on the ventral bar. The genera are distinguished by Mymarothecioides n. gen. having a dextro, midventral vaginal opening (middorsal or dextro-dorsal in Mymarothecium ) and by lacking eyespots (four eyespots in Mymarothecium ). These combined characters support the transfer of Mymarothecium whittingtoni Kritsky, Boeger & Jégu, 1996 to Mymarothecioides n. gen. as Mymarothecioides whittingtoni ( Kritsky, Boeger & Jégu, 1996) n. comb.