Holocentricola, Cutmore & Cribb, 2021

Cutmore, Scott C. & Cribb, Thomas H., 2021, A new order of fishes as hosts of blood flukes (Aporocotylidae); description of a new genus and three new species infecting squirrelfishes (Holocentriformes, Holocentridae) on the Great Barrier Reef, Parasite (Paris, France) 28 (76), pp. 1-17 : 3-6

Genus Holocentricola n. gen.

urn:lsid:zoobank.org:act:5A09F566-8340-4E4D-8EBA-

BA767D613365

Diagnosis

Body lanceolate, ventrally concave, broadest at level of testis or caeca, with distinct terminal notch at posterior end, and distinct bulge sometimes present at level of uterus. Tegumental spines arranged in ventro-marginal transverse rows for entire body length, straight for most of body length, those in final 5–10 rows slightly curved with small hook on tip. Rosethornshaped or fused spines absent. Oral sucker poorly delineated, weakly muscularised, bearing concentric rows of fine spines. Mouth ventrally subterminal. Oesophagus almost straight to gently sinuous, thick-walled. Caeca form X-shape; intestinal bifurcation in middle third of body. Anterior caeca equal to subequal in length, much shorter than posterior caeca. Posterior caeca equal to subequal in length. Testis single, roughly rectangular, with margins irregularly lobed, immediately posterior to posterior margin of posterior caeca, usually extends laterally beyond lateral nerve cords. External seminal vesicle absent. Vas deferens sometimes widening posteriorly. Cirrus-sac retort-shaped, rounded anteriorly, dramatically narrowed posteriorly; anterior rounded portion contains seminal vesicle and pars prostatica; posterior narrow portion notably thickened at marginal genital pore, contains ejaculatory duct. Seminal vesicle round to ovoid, restricted to anterior, rounded portion of cirrus-sac, joining coiled pars prostatica. Ejaculatory duct long. Male genital pore on sinistral margin at distinct to indistinct marginal notch. Ovary oblong, roughly rectangular or wedge-shaped, medial, with margins irregularly lobed, immediately posterior to testis, usually extending laterally beyond lateral nerve cords. Oviducal seminal receptacle present. Oötype posterior to rest of genitalia, medial to submedial. Uterus weakly convoluted, passing anteriorly between oviduct and dextral side of cirrus-sac, ventrally overlapping posterior portion of ovary, then passing posteriorly, sinistral to cirrus-sac, to female genital pore; distal portion of uterus often forming prominent egg reservoir, creating distinct marginal bulge. Female genital pore dorsal, sinistro-submedial, separate from and anterior to male pore. Eggs in utero ovoid to subspherical, very thin-shelled, anoperculate. Vitellarium follicular, distributed from just posterior to dorsal nerve commissure to posterior half of testis or level of ovary, laterally exceeding nerve cords, largely confluent anterior to testis. Excretory vesicle small, saccular. Excretory pore at apex of terminal notch. In circulatory system of holocentrid fishes.

Type species: Holocentricola rufus n. sp.

Other species: Holocentricola exilis n. sp.; Holocentricola coronatus n. sp.

Etymology: This genus is named for the order of fishes it infects (the Holocentriformes ) and the Latin - cola (dweller or inhabitant). It should be treated as masculine.