Uterine Seminal Receptacle Research Articles

RESURRECTION OF PLESIOCREADIUM WINFIELD, 1929 (DIGENEA: MACRODEROIDIDAE) WITH PHYLOGENETIC ANALYSES AND SUPPLEMENTAL OBSERVATIONS OF ITS TYPE SPECIES FROM RIVERS IN ARKANSAS, MISSISSIPPI, NEW YORK, AND TENNESSEE.

We herein resurrect and emend PlesiocreadiumWinfield, 1929 (Digenea: Macroderoididae) and provide a supplemental description of its type species, Plesiocreadium typicumWinfield, 1929, based on adult specimens collected from the intestine of bowfins, Amia calva Linnaeus, 1766 (Amiiformes: Amiidae), captured in the L'Anguille River (Mississippi River Basin, Arkansas), Big Lake (Pascagoula River Basin, Mississippi), Chittenango Creek (Oneida Lake, New York), and Reelfoot Lake (Tennessee River Basin, Tennessee). Plesiocreadium spp. (Pl. typicum and Plesiocreadium flavum [Van Cleave and Mueller, 1932] n. comb.) differ from other macroderoidids by having a dorsoventrally flat forebody, ceca that extend posteriad beyond the testes and that do not form a cyclocoel, testes that are greater than one-half of maximum body width, a cirrus sac that is dorsal to the ventral sucker and arches dextrad or sinistrad, a uterine seminal receptacle, asymmetrical vitelline fields that remain separated anteriorly and posteriorly and that extend anteriad to the level of the ventral sucker, and an I-shaped excretory vesicle. Bayesian phylogenetic analyses (ITS2 and 28S) recovered monophyletic Plesiocreadium sensu stricto (as defined herein) sister to Macroderoides trilobatusTaylor, 1978 and that clade sister to the remaining macroderoidids, with sequences ascribed to species of Macroderoides Pearse, 1924 recovered as paraphyletic. We regard Macroderoides parvus (Hunter, 1932) Van Cleave and Mueller, 1934, M. trilobatus, and RauschiellaBabero, 1951 as incertae sedis. Arkansas, New York, and Tennessee comprise new locality records for Pl. typicum.

A new genus and species of Anchitrematidae Mehra, 1935 (Digenea: Gorgoderoidea) in a freshwater fish from the River Nile at Qena, Egypt with amendation of the family.

Museum specimens of a previously unknown species of the Anchitrematidae from a freshwater fish collected from the River Nile at Qena, Egypt were examined. This species is somewhat similar to species of Anchitrema, but was found to have a thick, continuous, shelf-like rim around the periphery of the ventral aspect of the distome, the lateral aspect of the forebody was composed of large internal patches of lightly vacuolated, somewhat glandular cells that formed pad-like structures (pelops-like structures), and it possessed a uterine seminal receptacle; characteristics that previously have not been found in any species in the family. Species currently assigned to Anchitrema or Mujibia (the only two genera in the family) are known only from reptiles and mammals and no species has previously been reported from a freshwater fish. We feel that these differences are sufficient enough to warrant the erection of Piscianchitrema n. gen. and amendation of the family. We support the synonymies of Anchitrema congolense with Anchitrema latum, and Anchitrema lucknowensis with Anchitrema indicum. The current status of species previously described in the family is discussed, and keys to the genera and species of Anchitrema are provided.

Recovery of Oswaldotrema nacinovici from Whimbrels (Aves) in Korea.

Adult specimens of Oswaldotrema nacinovici (Digenea: Philophthalmidae) have been first identified in Korea from 2 migratory birds (whimbrels, Numenius phaeopus) which were found dead at a western seashore area near Gunsan. The worms were recovered in the intestine of these birds. The worms were morphologically characterized by a large ventral sucker in comparison to the oral sucker, an external seminal vesicle extending beyond the posterior margin of the ventral sucker, and conspicuous uterine seminal receptacle. It was noteworthy that metacercariae-like bodies were contained within the inflated regions of 2 ceca. Other intestinal trematode species found in whimbrels included Spelotrema pygmeum, Gynaecotyla squatarolae, Maritrema obstipum, and Himasthla megacotyle. Zoonotic potential of these trematode species should be taken into considerations.

The molecular phylogeny of the digenean family Opecoelidae Ozaki, 1925 and the value of morphological characters, with the erection of a new subfamily.

Large and small rDNA sequences of 41 species of the family Opecoelidae are utilised to produce phylogenetic inference trees, using brachycladioids and lepocreadioids as outgroups. Sequences were newly generated for 13 species. The resulting Bayesian trees show a monophyletic Opecoelidae. The earliest divergent group is the Stenakrinae, based on two species which are not of the type-genus. The next well-supported clade to diverge is constituted of three species of Helicometra Odhner, 1902. Based on this tree and the characters of the egg and uterus, a new subfamily, the Helicometrinae, is erected and defined to include the genera Helicometra, Helicometrina Linton, 1910 and Neohelicometra Siddiqi et Cable, 1960. The subfamily Opecoelinae is found to be monophyletic, but the Plagioporinae is paraphyletic. The single representative of the Opecoelininae (not of the type genus) is nested within a group of deep-sea 'plagioporines'. The two representatives of the Opistholebetidae are embedded within a group of shallow-water 'plagioporine' species. The Opistholebetidae is reduced to subfamily status pro tem as its morphological and biological characteristics are distinctive. This implies that as opecoelid systematics develops with more molecular evidence, several further subfamilies will be recognised. Many of the morphological characters were found to be homoplasious, but the characters defining the Helicometrinae and Opecoelinae, such as filamented eggs, reduced cirrus-sac and uterine seminal receptacle, are closely correlated with the inferred phylogeny.

New Genus and Species of Fish Blood Fluke (Digenea: Aporocotylidae Odhner, 1912) from Stoplight Parrotfish,Sparisoma viride(Bonnaterre, 1788), (Labridae: Scarinae) in the Caribbean Sea

Primisanguis caribbeanensis n. gen., n. sp. (Digenea: Aporocotylidae) infects the stoplight parrotfish, Sparisoma viride (Bonnaterre, 1788), (Labridae: Scarinae) in the Caribbean Sea off La Parguera (17°58'26" N, 67°02'47"W), Puerto Rico. It is most easily distinguished from other nominal aporocotylids by the combination of having an adult body that is approximately 5-10 times longer than wide, a sinistral posterolateral body protuberance, tegumental body spines that are straight (lacking recurved tip) and wrap dorsoventrally around the body margin, posterior ceca that are 2-5 times the anterior ceca length, a single testis that extends lateral to both the ceca and nerve cords, an ovary abutting the posterior margin of the testis, a symmetrical vitellarium and medial primary vitelline duct, a post-cecal and post-gonadal ootype, and a proximal uterus that is extensively convoluted posterior to the ootype and which functions as a uterine seminal receptacle. The new genus lacks a spinous anterior sucker, pharynx, auxiliary external seminal vesicle, cirrus stylet, oviducal seminal receptacle, and Laurer's canal. The new species is morphologically most similar to the other aporocotylids that have a posterolateral body protuberance, including species of Psettarium Goto and Ozaki, 1930, Aporocotyle Odhner, 1900, Ankistromeces Nolan and Cribb, 2004 , Phthinomita Nolan and Cribb, 2006, and Littorellicola Bullard, 2010, but it can be differentiated from them, at the least, by lack of a spinous anterior sucker in the adult and by the combination of having dorsoventral rows of tegumental spines, a testis dorsal to the posterior ceca, and a uterine seminal receptacle posterior to the ootype. The new species is the first aporocotylid reported from the Caribbean Sea or from a parrotfish of Sparisoma.

Two Cyclocoelids from the Lesser Yellowlegs, Tringa flavipes (Scolopacidae), from the Central Flyway of North America, Including the Description of Haematotrephus selfi n. sp. (Digenea: Cyclocoelidae)

Seven specimens of cyclocoelids (6 specimens representing Haematotrephus selfi n. sp. and 1 specimen representing a second unidentified species of Haematotrephus) collected by the late Dr. J. Teague Self, former professor, Department of Zoology, University of Oklahoma, Norman, Oklahoma, U.S.A., from the body cavities of 3 lesser yellowlegs, Tringa flavipes, (2 birds collected from Roger Mills County, Oklahoma on 23 and 29 August 1963, and 1 collected from Manitoba, Canada on 3 June 1964) and deposited in the Manter Laboratory of Parasitology, University of Nebraska, Lincoln, Nebraska are described. Haematotrephus selfi n. sp. can be distinguished from all other species in the genus that lack an oral sucker except Haematotrephus limnodromi by having intertesticular uterine loops. It most closely resembles H. limnodromi but differs from it by having a smaller body, a smaller pharynx, smaller testes, a shorter cirrus sac, and somewhat smaller eggs. In addition, H. selfi n. sp. lacks a uterine seminal receptacle.

Saccocoelium megasacculum n. sp., a new haploporid trematode from Liza carinatus in the Taiwan strait.

Saccocoelium megasacculum n. sp. (Digenea: Haploporidae) was collected from the intestine of the mugilid fish. Liza carinatus (Cuvier and Valenciennes), in the Taiwan Strait. It is the first record of Saccocoelium in China. The parasite most closely resembles Saccocoelium obesum Looss, 1902 and Saccocoelium tensum Looss, 1902 in general morphology and body size, but it is easily distinguished from them in having a larger hermaphroditic sac in relation to body size; larger eggs; smaller pharynx, testis, ovary, and vitellaria; and a uterine seminal receptacle instead of a true seminal receptacle.

Scorpidotrema longistipes n. g., n. sp. (Digenea: Opecoelidae) from Scorpis georgiana (Teleostei: Scorpididae) from southern Western Australia.

Scorpidotrema longistipes n. g., n. sp. is described from the intestine of Scorpis georgiana Valenciennes (Scorpididae) from off Point Peron, Western Australia. The new genus is distinguished by the combination of a remarkably long and retractable ventral sucker peduncle, a possible uroproct, well-developed cirrus-sac and a uterine seminal receptacle. The subfamilial relationships of the new genus are troublesome. It incorporates features of the Opecoelinae, Stenakrinae and Plagioporinae. The absence of a canalicular seminal receptacle suggests a relationship with the Opecoelinae and Stenakrinae, whereas the well-developed cirrus-sac suggests a relationship with the Plagioporinae and Stenakrinae. The overall arrangement of the gonads is not similar to that of existing genera of Stenakrinae. It is concluded that the genus is best placed in the Stenakrinae although that subfamily may now be an artificial assemblage. This new genus forms part of a distinctive fauna of trematodes restricted to Australian southern temperate fishes.

Lasiotocus lizae sp. n. (Digenea: Monorchiidae), a new trematode from marine fish in the Taiwan Straits, China.

Lasiotocus lizae sp. n. (Digenea: Monorchiidae) was collected from the intestine of Liza carinata (Valenciennes) (Mugilidae, Perciformes) in the Taiwan Straits, China. L. lizae is most similar to Lasiotocus glebulentus Overstreet, 1971 from the intestine of Mugil cephalus from the Northern Gulf of Mexico in having tightly compacted vitellaria, a genital pore sinistral to the midline, the ovary usually dextral to the acetabulum, the similar sucker ratio, and in the presence of both a canalicular and uterine seminal receptacle. It differs from L glebulentus in its cirrus sac ending anterior to rather than posterior to acetabulum, in the ending position of caeca, in smaller eggs, and in having a single rather than several conspicuous concretions in excretory vesicle.

The status of the genera Hysterolecithoides Yamaguti, 1934, Neotheletrum Gibson & Bray, 1979 and Machidatrema León-Règagnon, 1998 (Digenea: Hemiuroidea), including a description of M. leonae n. sp. from Australian waters.

A diagnosis is given for the lecithasterid genus Hysterolecithoides Yamaguti, 1934, which is now found to have two to six (possibly seven) vitelline masses. The species H. frontilatus (Manter, 1969) is returned to the genus, having been considered a member of the bunocotylid genus Neotheletrum by recent authors. It is redescribed from Siganus nebulosus, Moreton Bay, and S. doliatus, Lizard Island, Great Barrier Reef and New Caledonia, with emphasis on the presence of Juel's organ, a uterine seminal receptacle and the blind sac associated with the genital atrium. It differs from its congeners in the trajectory of the pars prostatica which recurves dorsally to the sinus-sac. Oligolecithoides Shen, 1982 is synonymised with Hysterolecithoides and O. trilobatus Shen, 1982 is synomised with H. epinepheli Yamaguti, 1934. Machidatrema León-Règagnon, 1998 is diagnosed, and found to be close to Hysterolecithoides, but differs in the lack of a blind-sac projecting from the dorsal genital atrium, by its tandem testes, the coiling of the uterus between the testes and the ovary, and the ventral excretory pore. M. leonae n. sp. is described from Siganus fuscescens, S. lineatus, S. doliatus, S. corallinus, S. vulpinus and Scarus globiceps at Heron Island, Queensland. It differs from its closest congener, M. akeh, in the muscular and tegumental flap over the genital pore and details of the terminal genitalia. M. chilostoma (Machida, 1980) and M. kyphosi (Yamaguti, 1970) are redescribed from Kyphosus vaigiensis from Heron Island. Neotheletrum Gibson & Bray, 1979 is diagnosed: it differs from Hysterolecithoides in its confluent excretory arms, blind seminal receptacle (no Juel's organ) and uniformly tripartite vitellarium. A cladistic analysis suggests that M. chilostoma and M. kyphosi are not best accommodated in Machidatrema, that Machidatrema (sensu stricto) is monophyletic and that Hysterolecithoides is paraphyletic. Hysterolecithoides and Machidatrema are considered hysterolecithine lecithasterids, whilst Neotheletrum is retained as an opisthadenine bunocotylid.

Proposed division of the genus Heterophyes Cobbold, 1865 (Trematoda : Heterophyidae).

A new genus, Alloheterophyes, is erected for Heterophyes chini Pearson & Pearson, 1983 and for H. superspinata Leonov & Belogurov, 1965, with which H. bitorquata Pearson & Pearson, 1983 is synonymised. New host and locality records are given. Alloheterophyes differs from Heterophyes in having: (i) a seminal vesicle of two tandem chambers, the distal with a thicker wall; (ii) a uterine seminal receptacle; (iii) an unspined genital atrium; (iv) an inflated, almost triangular excretory bladder; (v) a ventral sucker not close to the gut fork; (vi) the final loop of the uterus dextral to the gonotyl; and (vii) a clavate shape.

First record of shape Saturnius papernai Overstreet, 1977 in the Black Sea, with a review of the genus shape Saturnius Manter, 1969 (Digenea, Bunocotylidae)

Saturnius papernai Overstreet, 1977 is recorded from the stomach of Mugil cephalus L. (Osteichthyes, Mugilidae) in the Black Sea (a new geographical record) off the southern part of the Bulgarian coast. The species is redescribed and figured on the basis of the Black Sea specimens. Some amendments to the generic diagnosis are proposed concerning the presence of a uterine seminal receptacle and a posterior (third) circular flange. It is proposed that the occurrence of S. papernai is a feature of one of the three shoals of M. cephalus in the Black Sea, i.e. the Balkan shoal. In a zoogeographical analysis, S. papernai is regarded as a Mediterranean immigrant, probably a characteristic element of only the South-Western Faunistic Region of the Black Sea. A review of the genus Saturnius Manter, 1969 is presented.

A redescription ofLepidauchen stenostoma Nicoll, 1913 (Digenea), and a reassessment of the status of the genusLepidauchen Nicoll, 1913

The genusLepidauchen is discussed and defined. It is removed from the family Lepocreadiidae and placed in the family Acanthocolpidae based mainly on its possession of a uterine seminal receptacle. The type, and only valid species,L. stenostoma, is redescribed using material fromLabrus merula from Corsica. Material fromCoris julis andSymphodus tinca from the western Mediterranean off Marseille,L. merula from the western Mediterranean off Valencia,Diplodus annularis andLithognathus mormyrus from the Adriatic Sea off Montenegro, andArchosargus unimaculatus from Venezuela was also examined. Other nominal species are discussed, but none are considered valid within this genus.

The Acanthocolpidae (Digenea) of fishes from the north-east Atlantic: the status of Neophasis Stafford, 1904 (Digenea) and a study of North Atlantic forms

The genus Neophasis is defined. The taxonomic status of the genus is discussed in the light of its life-cycle, hosts and cercarial and adult morphology. It is considered to be closest to the family Acanthocolpidae due to the utilisation of a fish second intermediate host, the form of the cercarial excretory system and, in the adult, the presence of a uterine seminal receptacle and the absence of an external seminal vesicle. The taxonomic value of morphological features are discussed and a key to the north Atlantic species given. The following species are described: Neophasis oculatus (Levinsen) from Myoxocephalus scorpius off West Greenland (type-material), Norway and Denmark, Lycodes esmarkii off NW Scotland and the Faroes, and L. vahli off Newfoundland; N. burti n. sp. (distinguished from N. oculatus by sucker-ratio and testicular configuration) from Myoxocephalus octodecemspinosus off Nova Scotia (type-locality) and New Brunswick, also? immature in Gadus morhua from the Gulf of St. Lawrence; N. anarrhichae (Nicoll) from Anarhichas lupus in the North Sea and off the Faroes; and N. pusilla Stafford from A. lupus off ‘eastern Canada’ (type-material) and Nova Scotia. The only other species in the genus is N. symmetrorchis Machida from the NW Pacific Ocean.

Autoradiographic Studies on Reproduction in Philophthalmus megalurus (Cort, 1914) (Trematoda)

Incorporation of 3H-thymidine in gonial cells but not thereafter permitted timing of certain aspects of gametogenesis and studies on selfand cross-insemination. From oogonia until the primary oocyte is enclosed in the egg required from 7 days in 6-day-old worms to 13 days when 68 days of age. From labeled vitelline cells until their nuclei were detected in eggs required 96 hr. From tertiary spermatogonia to primary spermatocytes required 48 hr; to secondary spermatocytes, 60 hr; to spermatids, 96 hr; to sperm bundles, 120 hr; and to sperms in the seminal vesicle, 132 hr. Timing of the above events was not affected by the age of the worms after sexual maturity was attained. When 37 labeled worms, 6 to 90 days of age, were returned singly to the host for 6 to 16 days, 28 inseminated themselves as demonstrated by radioactive sperms in the female system. When each of 33 such worms was in the company of one to three nonlabeled worms of the same age, only one inseminated itself whereas the 33 inseminated 47 of 61 nonlabeled worms available. The extent of cross-insemination was less when only old worms were present but not when young and old worms were together, even though there was about a threefold size difference. Disappearance of labeled sperms from the uterine seminal receptacle within 14 to 16 days of copulation demonstrated a rate of turnover requiring repeated insemination during the life of the worms for continued production of viable eggs. Numerous papers have dealt with aspects of reproduction in digenetic trematodes but none has applied autoradiography to such studies. In investigating the incorporation of tritiated compounds by adults of Philophthalmus megalurus, it was found that various cells concerned with reproduction could easily be labeled in vitro with such compounds and followed by returning the worms to the host for various periods of time before they were prepared for autoradiography (Nollen, 1968). That study demonstrated that tyrosine is incorporated in vitelline cells to appear later in the eggshell, and that 10 days after labeling, eggs with labeled shells reach the metraterm and contain fully developed miracidia. Using the same materials and methods, other aspects of reproduction in P. megalurus were investigated as reported in the present paper. Nollen (1968) should be consulted for details of technique. OBSERVATIONS AND DISCUSSION

Studies on Echinostomatidae (Trematoda) in Malaya IX. The Mehlis' Gland Complex in Echinostomes

Observations on the functional anatomy of the ducts associated with Mehlis' gland were made in five species of echinostomes: Echinostoma malayanum, E. lindoense, E. audyi, Hypoderaeum dingeri, and a 43-spined, undescribed Echinoparyphium species. In all five species the structure of the Mehlis' gland complex is similar. There is an ovicapt in the form of a chamber which regulates the passage of the ova from the ovary into the oviduct. Ciliated epithelium lines the ovicapt, the oviduct distal to the ovicapt, and the proximal part of Laurer's canal. The movement of the cilia is directed toward Laurer's canal from which excess sperm and vitelline granules are discharged at the dorsal surface. Spermatozoa are stored in the uterine seminal receptacle in the absence of a seminal receptacle. The Mehlis' gland complex of echinostomes is best studied in living worms because the ducts and organs associated with it are not clearly visible in mounted specimens. Moreover, the gland region is often filled with eggs, making a detailed study extremely difficult or impossible. Descriptions are often incomplete and sometimes inaccurate. This paper reports observations on the Mehlis' gland complex in living specimens of five species (three genera) of echinostomes. MATERIALS AND METHODS The following species of echinostomes were studied: Echinostoma nmalayanum Leiper, 1911; E. lindoense Sandground and Bonne, 1940; E. audyi Lie and Umathevy, 1965; Hypoderaeum dingeri Lie, 1964; and an undescribed 43-spined Echinoparyphium species which will be named later when its complete life cycle is described. An unlimited supply of living worms was maintained in the laboratory for life-cycle studies. E. malayanum was obtained from rats, the other four species from pigeons and ducklings. Young adult worms with few eggs in the uterus were preferred. The Echinoparyphium species is the easiest to study since the worm is small and seldom contains many eggs; H. dingeri is the most difficult to examine due to thickness of the worm and density of Mehlis' gland. The living worm is examined dorsal side up in a drop of physiological saline under a cover slip. Received for publication 12 August 1964. * This work was supported by the University of California International Center for Medical Research and Training (The Hooper Foundation, San Francisco School of Medicine) with Research Grant GM-11329 from the Office of International Research, NIH, U. S. Public Health Service. t Present address: Hooper Foundation, University of California Medical Center, San Francisco. When movement of the worm is restricted and the position is suitable, ducts and organs in the Mehlis' gland region can be seen. An oil-immersion lens is required for detailed observation of certain parts.