Showing papers in "Journal of the Helminthological Society of Washington in 1997"

Distribution and prevalence of the Asian fish tapeworm, Bothriocephalus acheilognathi, in the Colorado River and tributaries, Grand Canyon, Arizona, including two new host records.

Abstract: The Asian fish tapeworm, Bothriocephalus acheilognathi, has invaded the lower Little Colorado River (LCR), a tributary of the Colorado River, where it infects humpback chub (Gila cypha), speckled dace (Rhinichthys osculus), and fathead minnow (Pimephales promelas). This study examined the distribution of R. acheilognathi in the Colorado River and tributaries in Grand Canyon. In 1994, 22.5% of humpback chub, 10.3% of plains killifish (Fundulus zebrinus), 3.8% of speckled dace, and 2.2% of fathead minnow were infected. In 1995, 2.4% of fathead minnow and 1.4% of speckled dace were infected. Humpback chub, an endangered species, and plains killifish are new host records for this parasite. Nearly all (66.7 to 100%) infected fish were captured in areas near the LCR and were probably the result of infected fish emigrating from that tributary. However, 4 infected fish (1 plains killifish, 1 speckled dace, and 2 fathead minnows) were caught 92.8 to 202.1 km downstream from the LCR. Another speckled dace was caught in the lower section of Kanab Creek, a warm tributary, indicating a potential expansion of the parasite's range. Infection of humpback chub by B. acheilognathi is of concern due to the endangered status of this fish. Because B. acheilognathi requires high water temperature for completion of its life cycle, this species is largely confined to the LCR by the cold water of the mainstem Colorado River. The potential effects of plans to seasonally warm the Colorado River on B. acheilognathi are discussed.

Digenetic trematodes of marine fishes from the Kuwaiti coast of the Arabian Gulf: family Monorchiidae Odhner, 1911.

Abstract: Two species of monorchiids are described from marine fishes of the Kuwaiti coast of the Arabian Gulf: Proctotrematoides kuwaiti sp. n. from Synaptura orientalis and Pseudorhombus arsius differs from all others in the genus by the absenc e of a prepharynx and esophagu s and by the arrangemen t and position of the vitelline follicles. Opisthodiplomonorchis elongatus Madhavi, 1974, is reported from Polydactylus sextarius and Plectorhynchus sp., both new locality records and the latter a new host record. Opisthodiplomonorchis differs from all monorchii d gener a with diagonal or tandem testes by the following combination of characteristics : vitellaria in 2 lateral groups of preand postovarian follicles, multilobed ovary, tandem testes at the posterior extremity, and unipartite seminal vesicle and terminal organ. Keys to the species of Proctotrematoides and monorchiids with 2 testes are included. Pseudomonorcheid.es Zhukov, 1983, nee Pseudomonorcheides Wang, 1982, is renamed Zlmkovtrema.

Helminth Parasites of Sea Otters (Enhydra lutris} from Prince William Sound, Alaska: Comparisons with Other Populations of Sea Otters and Comments on the Origin of Their Parasites

Abstract: The helminths found in the gastrointestinal tracts and gallbladders of 68 sea otters (Enhydra lutris) from Prince William Sound, Alaska, and their prevalences were: Corynosoma enhydri (Acanthocephala), intes- tine, 51.5%; Orthosplanchnus fraterculus (Trematoda), gallbladder, 50%; Diplogonoporus tetrapterus (Cestoda), intestine, 12%; and Pseudoterranova decipiens (Nematoda), stomach, 1.5%. One pup examined was free of helminth parasites. Throughout its range from the Kuril and Komandorski islands in Russia, across the Aleutian Islands, Alaska, and south to California, the sea otter harbors a total of 17 or 18 species of helminths, of which 5 or 6 are incidental infections with larval (2 species of Anisakis) or juvenile worms (3 or 4 species of Poly- morphus). The adult worms of sea otters (12 species) are derived primarily (9 species) from pinnipeds. One species, Microphallus pirum (Trematoda), found widely in sea otters from the Komandorski Islands to California, may be primarily a parasite of various shorebirds. Only one species, C. enhydri, is uniquely a parasite of sea otters, occurring throughout its range at prevalences greater than 50%. California populations of sea otters harbor only M. pirum, C. enhydri, and Polymorphus species, lacking any species known to be transmitted by fish; the diet of these sea otters consists almost entirely of invertebrates. Northern sea otter populations from Russia and Alaska have a more varied diet and are hosts for at least 5 fish-transmitted parasites. Among the commonly occurring parasites, the most striking difference between Russian and Alaskan populations of sea otters is the absence of O. fraterculus from Russian populations and its frequent occurrence in Alaskan populations.

Thubunaea ctenosauri sp. n. (Nematoda: Physalopteridae) from the iguanid lizard Ctenosaura pectinata and other lizard helminths from Mexico

Abstract: Thubunaea ctenosauri sp n is described from the large intestine of the iguanid lizard Ctenosaura pectinata from Aguamilpa, Mexican State of Nayarit It is characterized mainly by the position of the vulva, number and distribution of caudal papillae, length of spicules (0066 mm), and size of eggs (0054-0060 X 0039-0042 mm) Other recorded species of parasitic nematodes are Skrjabinodon scelopori from Phyllodactylus lanei; Parapharyngodon alvarengai from P lanei, Anolis nebulosus, and Sceloporus nelsoni; and Atractis sce- lopori from C pectinata and Sceloporus sp The findings represent new host records, and P alvarengai is reported from Mexico for the first time

Parasites of the dolphinfish (Coryphaena hippurus) in Puerto Rico

Abstract: Thirteen dolphinfish (Coryphaena hippurus) collected during 1993-1994 from La Parguera, Puerto Rico, were examined for parasites. Nine species of helminths were identified including 6 trematodes (Dinurus barbatus, D. breviductus, D. tornatus, Hirudinella ventricosa, Stepha.nostornurn coryphaenae, and Tetrochetus coryphaenae), 1 cestode (Tentacularia coryphaenae), 1 nematode (Hysterothylacium pelagicuni), and 1 acanthocephalan (Rhadinorhynchus pristis). Each dolphinfish was infected with at least 2 species of helminths (x = 4.7; range = 2 to 7 species). The most common helminths found were D. barbatus, H. pelagicuni, and Tetrochetus coryphaenae, with prevalences of 100, 92, and 62%, respectively. Each of the 13 hosts had a different composition of helminths. Crustacean parasites included Caligus balistae, C. coryphaena, C. productus, Dysgamus sp., Euryphorus nordmanni, and Pennella varians.

Helminths of 12 species of Anolis lizards (Polychrotidae) from the Lesser Antilles, West Indies

Abstract: Twelve species of anoles (Anolis aeneus, A. extremus, A. gingivinus, A. griseus, A. luciae, A. marmoratus, A. oculatus, A. richardi, A. roquet, A. sabanus, A. trinitatis, and A. wattsi) from the Lesser Antilles were examined for helminths. Twelve species of helminths were found: Mesocoelium monas, Oochoristica maccoyi, Oswaldocruzia marechali, Parapharyngodon cubensis, Spauligodon caymanensis, Trichospirura teixeirai, Abbreviata sp., Ascarops sp., Physaloptera sp., Physocephalus sp., Porrocaecum sp., and Centrorhynchus sp. Twenty-nine new host records are reported. The highest prevalence (75%) was P. cubensis in A. sabanus; greates t mean intensity (56.8) was S. caymanensis in A. marmoratus. The highest diversity of helminths was found in Anolis gingivinus, which harbored 9 species ; the lowest diversity occurred in A. trinitatis, which harbored 1 species . Islands with the greates t number s of helminth species are located in the northern Lesser Antilles.

Microfilariae in the Free-Ranging Florida Panther (Felis concolor coryi)

Abstract: Blood samples from Florida panthers (Felis concolor coryi) collected from 1986 to 1993 during the months of December through May were screened for the presence of microfilariae (mff) by the Difil® filter test. Thirty-five of 47 (74.5%) panthers older than 2 yr of age were positive with microfilaremias ranging from 10 to 7,380 mff/ml of whole blood. No panthers that were 6 mo of age or less (n = 10) were microfilariae- positive, and only 20% of the panthers in the 1-yr class (n = 5) were positive. A representative number of microfilariae (n = 40) from each of 7 freshly collected positive blood samples was measured and morphological characteristics were noted. The average length of microfilariae processed by the modified Knott's technique was 320 /Am (273-370 /Am) with a width of 4-5 /Am. Of the 280 microfilariae measured, 202 (72.14%) had tapered heads and straight tails with an average length of 319 /im (276-368 /Am), 61 (21.79%) had blunt heads and straight tails and averaged 323 /urn (274-366 /Am), 16 (5.71%) had tapered heads and button-hooked tails with an average length of 320 /Am (290-368 /am), and 1 (0.35%) had a blunt head and button-hooked tail and measured 320 /Am. The finding of no significant difference (P > 0.05) between length measurements due to differences in head and tail shape leads us to believe that all microfilariae were of 1 species. Based on micro- filarial length measurements, review of necropsy reports, and comparison with bobcat microfilariae, the most likely filarial species infecting the Florida panther is Dirofilaria striata (Molin, 1858).

Ultrastructure of the lesion nematode, Pratylenchus penetrans (Nemata: Pratylenchidae)

Abstract: Various stages of a lesion nematode , Pratylenchus penetrans (Cobb, 1917) Sher and Allen, 1953, were observed with transmission electron microscopy and low-temperatur e scanning electron microscopy (LTSEM) to elucidate the structural anatomy of the esophagus , intestine, and reproductive system. The lumen of the esophagu s is circular through the procorpus and triradiate in the metacorpus where it is part of the metacorpus pump valve. A pair of esophagea l lumen branches terminate as quadriradiat e valves in the subventral gland ampullae. The central lumen extends posteriad to become part of the esophago-intestina l valve. The enlarged intestinal lumen is delineated by scattered evaginated membrane s of the epithelial cells. The lumen may be occluded during nonfeeding periods or when the intestine becomes compresse d by the reproductive organs. The testis contains spermatocyte s with membrane-boun d nuclei that transform into amoeboi d spermatids with electron-opaque , nonmembrane-boun d nuclei surrounded by fibrous bodies. Spermatozo a with irregular clumps of nonmembrane-boun d chromati n surrounded by mitochondri a as well as residual fibrous bodies were found in seminal vesicles and vas deferens of males and in spermatheca e of female gonads. The ultrastructur e of the male and female reproductive organs is compared to similar features observed with light microscopy and

Neotropical monogenoidea. 30. Ancyrocephalinae (Dactylogyridae) of piranha and their relatives (Teleostei, Serrasalmidae) from Brazil : Species of Calpidothecium gen. n., Calpidothecioides gen. n., Odothecium gen. n., and Notothecioides gen. n.

Abstract: Two species of Calpidothecium, 2 species (1 new) of Calpidothecioides, 1 new species of Odothecium, and 1 new species of Notothecioides (Dactylogyridae, Ancyrocephalinae ) are described and/or reported from the gills of 4 species of Serrasalmida e from the Brazilian Amazon: Calpidothecium crescentis (Mizelle and Price, 1965) comb. n. (syn. Urocleidus crescentis Mizelle and Price, 1965), C. serrasalmus (Mizelle and Price, 1965) comb. n. (syn. Cleidodiscus serrasalmus Mizelle and Price, 1965), and Calpidothecioides pygopristi sp. n. from Pygopristis denticulata; Odothecium raphidiophallum sp. n. from Catoprion mento; and Notothecioides llewellyni sp. n. from Myleus torquatus and M. rubripinnis. Four new gener a are proposed: Calpidothecium is characterize d by dactylogyrids with a single vagina opening sinistrolaterally, 1 pair of eyes, overlapping gonads, a seminal vesicle representin g a dextral loop of the vas deferens , and a distal rod of the accessor y piece with terminal branches ; Calpidothecioides is characterize d by species with a double vagina (left branch opening sinistrolaterally, right branch looping right cecum and opening on the dorsomedia l body surface) , 1 pair of eyes, overlapping gonads, a seminal vesicle comprising a dextral loop of the vas deferens , and a simple termination of the distal rod of the accessor y piece; Odothecium is characterize d by helminths with a single vagina looping the left cecum and opening on the middorsal body surface, 2 pairs of eyes, overlapping gonads, a seminal vesicle representin g a dextral loop of the vas deferens , and a hook-shape d termination of the distal rod of the accessor y piece; Notothecioides is characterize d by species with the vagina looping the left cecum and opening on the middorsal body surface, 2 pairs of eyes, overlapping gonads, a sigmoid seminal vesicle, and a simple or hook-shape d termination of the distal rod of the accessor y piece. Urocleidus orthus Mizelle and Price, 1965, is transferred to Calpidothecioides.

Fessisentis acutulus (Van Cleave, 1931) comb. n. (Acanthocephala: Fessisentidae) : A parasite of caudate amphibians in North America, with comments on the single North American report of A. ranae (Schrank, 1788)

Abstract: Based on anatomical grounds, specimens in the type series of the acanthocephala n Acanthocephalus acutulus Van Cleave, 1931, from the red-spotted newt, Notophthalmus viridescens (Rafinesque, 1820), belong to the genus Fessisentis. This conforms with knowledge of the host-parasit e relationships within the genus Fessisentis. The single North American report for A. ranae (Schrank, 1788) clearly is not this species and probabl y is Acanthocephalus dims (Van Cleave, 1931) Van Cleave and Townsend, 1936.

Effects of exogenous reproductive hormones on Haemonchus contortus populations in lambs

Abstract: The potential roles of 2 reproductive hormones , prolactin and prostaglandin , in the regulation of nematode growth, fecundity, and survival in lambs were examined in 2 experiments . In the first experiment , prolactin (25 ILJ/lamb) was administered to 3 groups of lambs at 1-wk intervals during each of the first 3 wk of patency of Haemonchus contortus infections, respectively. Fecundit y (eggs/female/day ) and total daily egg production were significantly higher in the group treated with prolactin during week 2 of patency. Male worms were significantly longer, and female worms were significantly shorter after each weekly treatment with prolactin. In experiment 2, a prostaglandi n F2a analogue, BOVILENE® (0.25 mg/lamb), was injected daily with or without exogenous prolactin (25 lU/lamb) throughout the first 3 wk of patency, the period of highest egg production. BOVILENE treatment resulted in decrease d survival of both adult male and female worms and increased fecal egg concentrations , as estimated on a daily basi s throughout this period. The interactions of BOVILENE with prolactin were negative relative to total daily egg production and worm growth at the terminus of the experiment (day 42 postinoculation) . Additive or synergisti c effects of prolactin and BOVILENE were not evident relative to fecundity. Decrease d survival of worms from treatment with this potent prostaglandi n analogue alone is intriguing for parasit e control applications.