Podocotyle nimoyi
- Dataset
- Podocotyle nimoyi n. sp. (Digenea: Opecoelidae: Plagioporinae) and a re-description of Podocotyle pearsei Manter, 1934 from five species of deep-sea macrourids from the Gulf of Mexico and Caribbean Sea
- Rank
- SPECIES
- Published in
- Blend, Charles K., Dronen, Norman O., Armstrong, Howard W. (2016): Podocotyle nimoyi n. sp. (Digenea: Opecoelidae: Plagioporinae) and a re-description of Podocotyle pearsei Manter, 1934 from five species of deep-sea macrourids from the Gulf of Mexico and Caribbean Sea. Zootaxa 4117 (4): 491-512, DOI: 10.11646/zootaxa.4117.4.3
Classification
- kingdom
- Animalia
- phylum
- Platyhelminthes
- class
- Trematoda
- order
- Plagiorchiida
- family
- Opecoelidae
- genus
- Podocotyle
- species
- Podocotyle nimoyi
description
Description. [Based on 1 holotype and 4 paratypes. Measurements and proportions given in Table 2.] With characteristics of genus. Body triangular to longitudinally elongate; in triangular specimens, body widest in posterior third of body, anterior end attenuated to bluntly-rounded extremity, posterior end truncated with small invagination at extremity; in more elongate specimens body widest in posterior third of body. Forebody about 1 / 4 length of body, attenuate. Hindbody widens posteriorly toward midbody and beyond, truncates at posterior end of body. Tegument aspinose. Pre-oral lobe absent. Oral sucker subterminal, spherical to subspherical, unspecialized. Ventral sucker large, muscular, subspherical to transversely oval, unspecialized, sessile, conspicuous border around perimeter, aperture in mid- to anterior half of sucker, wider than long and almost as wide as entire worm at that level, larger than oral sucker, pre-equatorial at junction of first and second 1 / 4 of body. Prepharynx not observed. Pharynx muscular, subspherical to oval to dolioform in shape, anterior end ventrally-overlapped by oral sucker. Esophagus thin-walled anteriorly, more thick-walled posteriorly, short, straight (one specimen with slightly sinuous esophagus), longer than pharynx. Intestinal bifurcation anterior to ventral sucker in posterior half of forebody. Ceca thick-walled, parallel, variable in width being narrow anteriorly then gradually wider posteriorly with maximum width near posterior end of worm, terminates blindly near posterior extremity. Testes 2, tandem, median, irregularly indented to lobed, transversely elongate, contiguous, intercecal, postequatorial in posterior 1 / 3 of body. Post-testicular region confined to posterior fifth of body. Cirrus pouch distinct, thin-walled, clavate, slender, extends to posterior margin of ventral sucker or slightly posterior to it. Seminal vesicle internal, bi-partite; proximal portion small, saccate, in posterior or posterosinistral portion of cirrus pouch; distal portion narrow and extensively coiled, winds throughout posterior 1 / 2 to 3 / 5 of cirrus pouch. Pars prostatica indistinct, long, thick-walled; ejaculatory duct thick-walled with numerous dark-stained cells lining duct, 16 [n = 1] long; cirrus short; prostatic gland cells well-developed, distributed throughout cirrus pouch, most numerous in posterior half and at very distal portion of cirrus pouch. Genital pore submedian (sinistral), pre-acetabular, bifurcal to just pre-bifurcal at level of lower esophagus. Genital atrium distinct, oval. Ovary large, 3 - to 4 - lobed (some lobes inconspicuous), submedian to markedly dextral, anterior to but not contiguous with anterior testis, separated from latter by loops of uterus, equatorial to just post-equatorial in middle third of body. Seminal receptacle canalicular, large, median to submedian (dextral), postero-dorsal to and overlaps posterior margin of ovary, anterior to anterior testis. Laurer’s canal present; entire course of canal not observed but it passes dorsal to ovary; distal end expected to open dorsally to exterior. Vitelline reservoir conspicuous, median, sinistral at mid-ovarian level to posterosinistral to ovary, directly anterior to anterior testis and dorsal to uterus. Vitelline ducts at mid-ovarian level, pass medially anterior to anterior testis, bifurcate to left and right of vitelline reservoir along midline of worm to form longitudinal ducts; right vitelline duct passes dorsally over posterior half of ovary before it bifurcates. Oviduct inconspicuous, originates from medial side of lobe of ovary and runs short course to oötype, itself surrounded by conspicuous, dark-stained Mehlis’ gland cells, directly to left and at level of ovary, immediately anterior to or dorsally overlapped by vitelline reservoir, ventrally overlapped by uterine loops posteriorly. Uterus extensive, intercecal, wider posteriorly; uterine loops pass directly to left of ovary then extend down posteriorly over anterior testis as far as inter-testicular area before they turn and proceed anteriorly, loops narrow as they pass dorsally over ventral sucker then turn slightly anterosinistral to pass directly dorsal to and alongside distal portion of cirrus pouch prior to entering genital atrium. Metraterm conspicuous, thick-walled, occasionally dilated, extends from genital pore to near anterior margin of ventral sucker, 160 – 324 (242) [n = 2] long × 36 – 40 (38) [n = 2] wide. Vitellarium large (observed occasionally to be smaller-sized directly lateral to anterior testis), follicular, numerous, subglobular to globular to elongate in shape, circumcecal in uninterrupted lateral bands, extends from posterior extremity anteriorly up to level of posterior margin of ventral sucker (3 individuals each with left lateral band and 1 individual with right lateral band of vitelline follicles that failed to extend to ventral sucker [see Table 2]; 1 specimen with right lateral band of follicles that extend to mid-level of ventral sucker), encroaches over lateral margins of gonads, not confluent in pre-ovarian region, in space between ovary and anterior testis and in inter-testicular region, confluent in post-testicular region. Eggs collapsed and / or crenulated, relatively small, operculate, amber, non-filamented, numerous, densely packed in uterus, with nib on one pole. Excretory vesicle tubular, observed to extend at least to posterior testis; excretory pore terminal.
discussion
Remarks. Based on its possession of a canalicular seminal receptacle and a well-developed cirrus pouch enclosing an internal seminal vesicle, P. nimoyi n. sp. is assigned to the Plagioporinae within the Opecoelidae (Cribb 2005). The new species keys to the genus Podocotyle based on its possession of the following diagnostic combination of morphological characters: an egg lacking a unipolar filament and having a length> 40 – 50 µm; blindly-ending ceca; a round to transversely oval, non-pedunculate and unspecialized ventral sucker; vitellarium that are restricted to the hindbody, post-testicular and extend to the posterior end of the body; two tandem testes; an oral sucker that is not funnel-shaped; an excretory vesicle that is neither diverticulate nor enters the forebody; a clearly submedian genital pore; a pre-testicular uterus (while a few loops of the uterus extend into the intertesticular region in P. n i m oy i n. sp., the majority of the uterus is pre-testicular); and an ovary that is deeply lobed (Cribb 2005).
etymology
Etymology. The species designation is named in honor of the passing of Leonard Nimoy, an actor in the Star Trek television series and movies. His fictional character, Mr. Spock, and his career strongly influenced one of us (CKB) in childhood to pursue a career in science.
Name
- Homonyms
- Podocotyle nimoyi