Paravitellotrema overstreeti from the freshwater stingray Potamotrygon magdalenae in northern Colombia most closely resembles P. thorsoni by possessing a muscular sinus organ and sinus sac as well as exhibiting a saccate rather than elongate prostatic vesicle, It differs by possessing lobate rather than spherical vitellaria, a smaller sinus organ and sinus sac, elongate rather than diamond-shaped prostatic cells enclosed in a delicate membrane rather than free in the parenchyma, and a metraterm joining the hermaphroditic duct immediately anterior to the prostatic vesicle rather than at the base of the sinus organ

Brooks, Daniel R.

Mayers, Monte A.

Thorson, Thomas B.

English

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Faculty Publications from the Harold W. Manter
Laboratory of Parasitology Parasitology, Harold W. Manter Laboratory of
1979
Paravitellotrema overstreeti Sp. n. (Digenea:
Hemiuridae) from the Colombian Freshwater
Stingray Potamotrygon magdalenae Dumeri
Daniel R. Brooks
University of Notre Dame, dnlbrooks@gmail.com
Monte A. Mayers
University of Pennsylvania School of Veterinary Medicine
Thomas B. Thorson
University of Nebraska-Lincoln
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Brooks, Daniel R.; Mayers, Monte A.; and Thorson, Thomas B., "Paravitellotrema overstreeti Sp. n. (Digenea: Hemiuridae) from the
Colombian Freshwater Stingray Potamotrygon magdalenae Dumeri" (1979). Faculty Publications from the Harold W. Manter Laboratory
of Parasitology. 838.
https://digitalcommons.unl.edu/parasitologyfacpubs/838
Proc. Helrnintho1 • Soc. Wash. 
46(1) , 1979, pp, 52-54 
Paravitellotrema overstreeti Sp. n. (Digenea: Hemiuridae) 
from the Colombian Freshwater Stingray 
Potamotrygon magdalenae DumeriF 
DANIEL R BROOKs,2 MONTE A. MA YES,3 AND THOMAS B. THORSON4 
ABSTRACT: Paravitellotrema overstreeti from the freshwater stingray Potamotrygon magdalenae in 
northern Colombia most closely resembles P, thorsoni by possessing a muscular sinus organ and 
sinus sac as well as exhibiting a saccate rather than elongate prostatic vesicle, It differs by possessing 
lobate rather than spherical vitellaria, a smaller sinus organ and sinus sac, elongate rather than 
diamond-shaped prostatic cells enclosed in a delicate membrane rather than free in the parenchyma, 
and a metraterm joining the hermaphroditic duct immediately anterior to the prostatic vesicle rather 
than at the base of the sinus organ, 
Digeneans of the family Hemiuridae Luhe, 1901, subfamily Halipeginae 
Ejsmont, 1931 parasitize marine, brackish, and freshwater fishes, amphibians, 
and occasionally snakes. Twelve of 39 (30.7%) specimens of the freshwater sting-
ray Potamotrygon magdalenae Dumeril collected in "cienagas" of the Rio Mag-
dalena in northern Colombia during the summers of 1975 and 1976 hosted one to 
13 specimens of a new species of halipegine. This is the first report of an hali-
pegine occurring as an apparently normal constituent of any elasmobranch's hel-
minthofauna. 
The digeneans were removed from hosts, flattened with minimal coverslip pres-
sure, fixed with warm AFA, and stored in 70% ethanol. They were stained with 
Mayer's or Van Cleave's hematoxylin and mounted in Histoclad for study as 
whole mounts . Measurements are in micrometers unless otherwise stated; figures 
were drawn with the aid of a drawing tube. 
Paravitellotrema overstreeti sp. n. 
(Figs. 1-3) 
DESCRIPTION (based on 25 specimens): Body elongate, subcylindrical, lacking 
ecsoma, 1.60-2.38 mm long by 0.56-0.74 mm wide at acetabulum. Preoral lobe 
present. Oral sucker 174-228 long by 216-264 wide, subterminal. Acetabulum 
300-438 long by 325-444 wide. Forebody 38-43% (40%) of total body length. 
Ratio of oral sucker width to acetabular width 1: 1.48-1.57 (1: 1.53). Prepharynx 
lacking. Pharynx 72-114 long by 78-108 wide. Ratio of oral sucker width to 
pharyngeal width 1:0.34-0.38 (1:0.36). Esophagus lacking; saccate crop present 
at cecal bifurcation. Cecal bifurcation 28-33% (30%) of total body length from 
anterior end; ceca extending near posterior end of body. 
Testes in anterior half of hind body , spherical to subspherical, diagonal , in terce-
calor ventral to ceca. Left testis 156-180 long by 150-204 wide; right testis 150-
186 long by 150-192 wide . Posttesticular space 28-32% (30%) oftotal body length. 
1 Funds for this study were provided through a grant from the National Geographic Society to the 
third author, 
2 Department of Biology, Notre Dame University, Notre Dame, Indiana 46556, 
3 Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Phila-
delphia, Pennsylvania, 
4 School of Life Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, 
OF WASHINGTON, VOLUME 46, NUMBER I, JANUARY 1979 • 
E 
E 
53 
Figures 1-3. Paravitellotrema overstreeti, 1. Ventral view of holotype. 2. Female ducts, 3. Terminal 
genitalia. Abbreviations: L = Laurer's canal; M = Mehlis' gland; MT = metraterm; H = hermaph. 
roditic duct; 0 = sinus organ; P = prostatic vesicle; R = vitelline receptacle; S = sinus sac; V = sem· 
inal vesicle. 
Seminal vesicle preacetabular, elongate to C- or U-shaped, 144-247 long, Narrow 
tubular anterior portion of seminal vesicle entering saccate prostatic vesicle 58-
100 long by 29-102 wide; prostatic vesicle surrounded by elongate prostatic cells 
enclosed in delicate membrane; limits of membrane 102-157 long by 78-137 wide. 
Prostatic vesicle joining tubular hermaphroditic duct emptying into muscular pro-
trusible sinus organ 44-96 long by 41-87 wide at widest point when not protruded. 
Sinus organ surrounded by thick-walled sinus sac 90-200 long by 80-176 wide. 
Genital pore ventral to posterior part of oral sucker, 9-12% (10%) of total body 
length from anterior end. 
Ovary posttesticular, 11-16% (12%) of total body length from posterior end, 
spherical to subspherical, 96-144 long by 96-150 wide. Uterine seminal receptacle 
present. Mehlis' gland and Laurer's canal postovarian. Laurer's canal a simple 
tUbe opening dorsally. Vitellaria compact, paired, deeply to shallowly lobate, 
ventral to ceca, immediately postovarian. Left vitellarium 90-210 long by 90-126 
Wide; right vitellarium 120-204 long by 90-150 wide. Uterus looping in intercecal 
54 . PROCEEDINGS OF THE HELMINTHOLOGICAL SOCIETY 
space from posterior margin of ovary to near level of prostatic vesicle; terminating 
in short muscular metraterm entering hermaphroditic duct immediately anterior 
to prostatic vesicle. Eggs with single polar filament, 44-46 (45) long by 20-23 (21) 
wide excluding filament; polar filament 2-3 times longer than egg. 
Excretory pore terminal; vesicle Y-shaped with arms uniting dorsal to pharynx. 
HOST: Potamotrygon magdalenae Dumeril, Colombian freshwater stingray. 
SITE OF INFECTION: Stomach. 
LOCALITIES: Cienaga Jobo, Rio Magdalena, vic. San Cristobal, Bolivar, Co-
lombia (type); Cienaga de Rabon, Rio Magdalena, vic. San Cristobal, Bolivar, 
Colombia. 
HOLOTYPE: USNM Helm. CoIl. No. 74730. 
PARATYPES: USNM Helm. Coli. No . 7473l. 
ETYMOLOGY: The species is named in honor of Dr. Robin M. Overstreet, Gulf 
Coast Research Laboratory, in recognition of his contributions to helminth tax-
onomy and ecology. 
Remarks 
Watson (1976) proposed the genus Paravitellotrema for two species parasitizing 
Nicaraguan freshwater fishes which resembled Vitellotrema Guberlet, 1928 by 
having the seminal vesicle and prostatic vesicle free in the parenchyma but which 
differed in possessing a sinus sac and in lacking the swollen terminal portion of 
the uterus unique to Vitellotrema. Paravitellotrema overstreeti most closely re-
sembles P. thorsoni Watson, 1976 by possessing a protrusible sinus organ and 
saccate rather than elongate prostatic vesicle. It differs by having lobate rather 
than smooth vitellaria, a smaller sinus organ and sinus sac, elongate rather than 
diamond-shaped prostatic cells which are enclosed in a delicate membrane rather 
than free in the parenchyma, and a metraterm joining the hermaphroditic duct 
immediately anterior to the prostatic vesicle rather than at the base of the sinus 
organ. Paravitellotrema astyanactis Watson, 1976, the only other member of the 
genus, lacks both sinus organ and saccate prostatic vesicle, characteristics which 
Manter (1969, 1970) and Watson (1976) did not consider of generic importance. 
Acknowledgments 
We express appreciation to Guillermo Quinones Gonzales, Director, Centro de 
Investigaciones Limnologicos y Piscicola, INDEREN A/F AO-San Cristobal, for 
aid and cooperation during the course of our study. 
Literature Cited 
Manter, H. W. 1%9. Some digenetic trematodes of marine fishes of New Caledonia. Part IV. Hemi-
uridae and summary. Proc. Helminthol. Soc. Wash. 36: 194-204. 
Manter, H. W. 1970. The terminology and occurrence of certain structures of digenetic trematodes, 
with special reference to the Hemiuroidea. H. D. Srivastava Comm. Vol. pp. 27-33. 
Watson, D. E. 1976. Digenea of fishes from Lake Nicaragua. Pages 251-260 in T. B. Thorson, ed., 
Investigations of the Ichthyofauna of Nicaraguan Lakes. School of Life Sciences, University of 
Nebraska-Lincoln, Lincoln, Nebraska. 


\u3ci\u3eParavitellotrema overstreeti\u3c/i\u3e Sp. n. (Digenea: Hemiuridae)
from the Colombian Freshwater Stingray
\u3ci\u3ePotamotrygon magdalenae\u3c/i\u3e Dumeri

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1849&amp;context=parasitologyfacpubs

\u3ci\u3eParavitellotrema overstreeti\u3c/i\u3e Sp. n. (Digenea: Hemiuridae) from the Colombian Freshwater Stingray \u3ci\u3ePotamotrygon magdalenae\u3c/i\u3e Dumeri

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