Polystoma nacialtuneli n. sp. (Monogenea: Polystomatidae) from the eastern spadefoot, Pelobates syriacus (Pelobatidae) in Turkey

Polystoma nacialtuneli n. sp. is described from the urinary bladder of the eastern spadefoot, Pelobates syriacus from Turkey. This is the fifth polystome species known from Turkey and the third species in Pelobates. We show that this new parasite species can be distinguished from other polystome species in the area by a combination of characteristics, including parasite size and the shape and size of the hamuli. Polystoma pelobatis from Pelobates cultripes has a pair of well-developed hamuli, while P. fuscus from Pe. fuscus characteristically has a pair of underdeveloped hamuli barely larger than the marginal hooklets. Polystoma nacialtuneli n. sp. has well-developed hamuli that vary significantly in shape. Phylogenetic relationships of P. nacialtuneli n. sp. within Polystoma, supplemented with molecular divergences estimated from internal transcribed spacer 1 (ITS1) sequences, indicate that they are well separated from their closest relatives, i.e. P. fuscus and P. pelobatis from Pe. fuscus and Pe. cultripes, respectively.     

Morphology and molecular characterization of Polystoma goeldii n. sp. (Monogenea,Polystomatidae) parasite from the urinary bladder of Physalaemus ephippifer (Steindachner) (Anura,Leptodactylidae)

Polystomatid flatworms of amphibians are represented in the Neotropical realm by species of Mesopolystoma, Nanopolystoma, Parapseudopolystoma, Polystoma, Riojatrema and Wetapolystoma but only species of Polystoma are known from Brazil, namely Polystoma cuvieri, P. knoffi, P. lopezromani and P. travassosi. During a survey of monogeneans infecting amphibians in the north-eastern region of Pará State, the Cayenne Caecilian Typhlonectes compressicauda was found to be infected with Nanopolystoma tinsleyi and the Veined Tree Frog Trachycephalus typhonius was found to harbor Polystoma lopezromani. A yet unknown species of Polystoma was also encountered in the urinary bladder of the Steindachner's Dwarf Frog, Physalaemus ephippifer. This new species, which is the second species reported from Physalaemus spp., is described herein as Polystoma goeldii n. sp. and its life cycle is also illustrated. The new species can be distinguished from Polystoma spp. from other neotropical realm by a combination of characteristics, including hamuli morphology, outer/inner hamuli length ratio, haptor/total body length ratio, genital bulb/total body length ratio, genital spine number and COI molecular characters.     

Polystoma fuscus n. sp. (Polystomatidae) from the common spadefoot Pelobates fuscus (Pelobatidae) in Bulgaria

Polystoma fuscus n. sp. (Polystomatidae, Polystomatinae) is described from the urinary bladder of Pelobates fuscus (Pelobatidae) in Bulgaria. Its general morphology is similar to that of other members of the genus but distinguished from them by the underdeveloped hamuli similar to the larval hamular primordia. The new species is also differentiated from the members of the genera of the subfamily Polystomatinae described without hamuli.     

A new species of Polystoma (Monogenea: Polystomatidae) parasitic in Hyperolius marmoratus (Anura: Hyperoliidae) in South Africa

Polystoma marmorati n. sp. is described as a new polystomatid species parasitic in the urinary bladder of the painted reed frog Hyperolius marmoratus marmoratus collected in southern Natal, South Africa. Parasite prevalence varied from 14.5 to 47.4% and the mean intensity from 1.0 to 1.1. The hamuli of the new species have a characteristic, partly fragmented appearance, a feature also seen in Polystoma batchvarivi, the only other polystome described from a species of the genus Hyperolius. The similarity between the two species, in spite of their geographical separation, is commented upon.     

Polystoma macrocnemis n. sp. (Monogenea: Polystomatidae) from the Iranian longlegged wood frog Rana macrocnemis (Ranidae) in Turkey

Polystoma macrocnemis n. sp. (Polystomatidae) is described from the urinary bladder of Rana macrocnemis (Ranidae) in Turkey. Its general morphology is similar to that of other members of the genus, but it is distinguished from closely related species by numerical parameters of the hamuli and also by its host species and geographical range.     

Study of closely related species within the Physalaemus cuvieri group (Anura): contribution of microsatellite markers

Various species of the Physalaemus cuvieri group of frogs are difficult to distinguish morphologically, making molecular analysis an attractive alternative for indentifying members of this group, which is considered to be at risk because of loss of habitat. The genetic structure of natural populations of P. ephippifer and P. albonotatus species was investigated and analyzed, together with that of five previously studied populations of P. cuvieri. Nine microsatellite loci were used in the analyses. The overall G(ST) value (0.46) revealed high genetic variation among the populations, as expected for different species. Bayesian analysis implemented by the STRUCTURE software clustered the seven populations into seven groups (K = 7). All the P. albonotatus and P. ephippifer specimens were grouped into a single cluster, both species showing clear differentiation from P. cuvieri. The different grouping based on these microsatellites of some P. cuvieri individuals from Porto Nacional and from Passo Fundo suggests that they could be a new species, indicating a necessity for taxonomic reevaluation. Despite the intrinsic difficulties in analyzing closely related species, the nine microsatellite loci were found to be adequate for distinguishing these three species of the P. cuvieri group and their populations.     

Foraging mode of a Madagascan iguanian lizard, Oplurus cuvieri cuvieri

The foraging mode of lizards has been extensively studied in members of most major families. One neglected taxon is Opluridae, a distinct Iguanian group endemic to Madagascar. We studied the foraging mode of Oplurus cuvieri cuvieri in a dry forest in north-western Madagascar. Quantitative data on the number of movements per minute and percentage of time spent in moving indicated that O. c. cuvieri is a typical ambusher, although the lizard occasionally fed on plant materials by active foraging. Possible seasonal changes in foraging activity were suggested. The results support the previous view that insectivorous iguanian lizards are ambush foragers.     

华西雨蛙寄生多盘虫科单殖吸虫一新种

在云南省新平县(24°N,101°32’E)采集的华西雨蛙Hyla a.annectans膀胱内检获多盘虫属1新种,新平多盘虫Polystoma xinpingensis sp.nov.。124只华西雨蛙中18只华西雨蛙感染,自然感染率为14.5%。新种与多盘虫属记录种最显著的区别在于:虫体体型小,其体长仅为2967μm。内侧肠管于虫体后1/3处仅形成2条横跨虫体的联合肠管,其它记录种肠管分支多数或形成较复杂的网状。睾丸巨大,呈滤泡状,分散分布直达虫体中部。新种的正、副模式标本保存在云南师范大学生命科学学院。     

Karyological analysis of Proechimys cuvieri and Proechimys guyannensis (Rodentia, Echimyidae) from central Amazon

The aim was to characterize the karyotype of rodents of the genus Proechimys from three localities in the central Brazilian Amazon, in the search for new markers that might shed light on our understanding of the taxonomy and evolutionary history of this taxon. Two karyotypes were found, viz., 2n = 28, FN = 46 in individuals from the NRSP (Cuieiras River) and REMAN (Manaus), and 2n = 46, FN = 50 in individuals from the Balbina Hydroelectric Plant. While individuals with the karyotype with 2n = 28 chromosomes were morphologically associated with Proechimys cuvieri, their karyotype shared similarities with those of the same diploid number in two other regions. Although three karyotypes are described for Proechimys cuvieri, no geographic distribution pattern that defined a cline could be identified. Based on the morphological examination of voucher specimens and additional results from molecular analysis, the karyotype with 2n = 46 and FN = 50 could be associated with P. guyannensis.     

Sperm cryopreservation in three species of endangered gazelles (Gazella cuvieri,G. dama mhorr,and G. dorcas neglecta)

Long-term storage of semen by cryopreservation, with high recovery rates on thawing, is essential for the establishment of genetic resource banks of endangered species. The purpose of the present study was to evaluate various diluents for the cryopreservation of spermatozoa from three species of gazelles (genus Gazella) in a captive breeding program. The diluents compared were Tes (N-tris(hydroxymethyl)methyl-2 aminoethane sulfonic acid)-Tris with 5% egg yolk and 6% glycerol (TEST) and Triladyl, yolk-citrate, Tris-trehalose, and Tris-lactose-all of them with 20% egg yolk and 6% (Triladyl) or 8% glycerol. Semen was obtained by electroejaculation from 12 G. cuvieri, 12 G. dama, and 13 G. dorcas males. Samples with less than 50% motile sperm, positive endosmosis, or acrosome integrity were not used. Diluted samples were loaded into 0.25-ml straws, cooled slowly to 5 degrees C over 1.5 h (-0.16 degrees C/min), equilibrated at that temperature for 2 h, frozen in nitrogen vapors for 10 min, and plunged into liquid nitrogen. Subsamples were assessed fresh, after refrigeration-equilibration, after freezing and thawing, and 2 h after thawing. Differences were seen between diluents, with best overall recovery rates after freezing and thawing found with Triladyl, TEST, and Tris-trehalose in G. cuvieri, TEST in G. dama, and Triladyl and TEST in G. dorcas. Differences were observed between species in the ability to withstand freezing and thawing, with best results seen in G. dorcas, intermediate results in G. dama, and worst results in G. cuvieri. These differences were inversely related to the average values of inbreeding of these populations. The underlying mechanism responsible for these differences may be a differential resistance to osmotic shock.     

Some aspects of the reproductive biology of Acanthopagrus spp. (Family: Sparidae)

Changes in the seasonal development of the gonads in Acanthopagrus latus and A. cuvieri over an annual reproductive cycle are described. There is one major spawning period from January to March. Hermaphrodite A. latus and A. cuvieri constituted 5.8% and 5.7% of the total sample respectively. The histological changes in the ovary, testis and ovo-testis in both species are described. Fecundity estimates for A. latus , 27.5–31.8 cm, ranged from 1 362 137 to 2 152 993, and estimates for A. cuvieri , 47.1–63.5 cm, ranged from 308 273 to 1 693 365.     

Hematologic and biochemical observations in Gazella dama, G. dorcas and G. cuvieri.

1. Blood samples obtained from 114 animals of three species of the genus Gazella (Gazella dama, Gazella dorcas and Gazella cuvieri) were analyzed from hematology (osmotic fragility, red blood cells morphology and hemoglobin electrophoresis) and biochemical values (glucose-6-phosphate dehydrogenase, pyruvate kinase and glutathione reductase deficiencies and superoxide dismutase activity). 2. Standard methods were used. Hemoglobin polymorphism was found. 3. There was no abnormality in the osmotic fragility and red blood cells morphology. 4. The biochemical results are compared with information from the literature and with the normal human range.     

Diplectanum squamatum n.sp. (Monogenea:Diplectanidae) fro the gills of Cynoscion guatucupa (Sciecidae) in southwest Atlantic waters

Diplectanum squamatum n. sp. is described from the gills of the sciaenid Cynoscion guatucupa collected off Mar del Plata, Argentina. The new species is distinguished from other species of the genus by the morphology of the hamuli and the male copulatory organ, and presence of scales on the haptor and body. This is the first species of Diplectanum to be reported from southwest Atlantic waters and, with the possible exception of D. cayennense Euzet & Durette-Desset, 1974, the only species from the Atlantic coast of South America.     

Use of tooth impressions to identify and age live Proechimys guyannensis and P. cuvieri (Rodentia: Echimyidae)

A technique whereby impressions of the cheekteeth were used to identify and age live Proechimys guyannensis and P. cuvieri is presented and tested. Based on tooth eruption and occlusal surface wear, 15 age classes were defined. Used in concert with a body measurement, measurements of the length of the toothrow and age class allowed almost all live individuals of the two species to be distinguished. The relationship between mean cheektooth length and hind foot length was most useful for distinguishing relatively old individuals, whereas the relationship between hind foot length or head-plus-body length and toothrow age class was most useful for distinguishing younger individuals. Mean eye lens weight of P. guyannensis increased with toothrow age class, suggesting that the toothrow age classes successfully measured relative age. Individuals of P. guyannensis in lower age classes had juvenile or subadult pelage and did not show signs of reproductive activity, whereas individuals in higher age classes had adult pelage and approximately 50% showed signs of reproductive activity. In the central Amazon, P. cuvieri was found to be proportionally more abundant relative to P. guyannensis in early-successional and edge-dominated habitats.     

Evolution of the tegument of Polystoma (Monogenea Polystomatidae) during the cycle. Persistence of the nucleated embryonic epidermis in oncomiracidia (author's transl)]

The evolution of tegument ultrastructures during development was studied in two Polystome species, Polystoma integerrimum and Polystoma pelobatis. It differs from Monogenea and other Platyhelminths in the presence of nuclei in the tegumentary syncytium of the oncomiracidium and their deferred elimination which occurs in the post-larva attached to the gills of the tadpole. This represents a delay in the loss of embryonic characteristics in Polystoma larvae which may be related to the possibility of neotenic development of these larvae. This delay allows us to follow naturally the considerable cytoplasmic changes which accompany the elimination of embryonic nuclei (disappearance of the ergastoplasm, golgi complexes and ribosomes, and of the vacuoles) and the transfer of control of this "enucleated" cytoplasm to nuclear information from tegumentary parenchymatic cells (appearance of new inclusions in the "annexed" cytoplasmic zone, maintenance of numerous organelles involved in the formation of these inclusions in the deep perinuclear region). The ultrastructual characteristics of ciliated cells and the tegumentary syncytium are discussed from the general point of view of the Platyhelminths and with respect to their adaptative function in the Polystomatidae. The originality of the Polystomatidae among the Monogenea is emphasized.     

Polystomatidae (Monogenea) of Anura in southern Africa: Polystoma testimagna n. sp. parasitic in Strongylopus f. fasciatus (Smith, 1849)

Polystoma testimagna n. sp. is described as a new species of the Polystomatidae, parasitic in the urinary bladder of the striped stream frog Strongylopus f. fasciatus collected in the Vernon Crookes Nature Reserve, Natal, South Africa. Parasite prevalence was found to be 50.0% and 27.7% in two successive years, and the mean intensity was 1.5 and 1.6, respectively. The species occurs together with another Polystoma species in the same water body and within one kilometre from a third species. Aspects of host specificity are discussed and data on the ecology and distribution of the host presented.     

Abscessed bony areas on Acanthopagrus cuvieri (Day) as a substrate for epiphytic algae

Enteromorpha compressa (L.) Greville and E. clathrata (J. Agardh), widely distributed green algae in Arabian Gulf, were observed growing on Acanthopagrus cuvieri (Day). Abscessed areas on the operculum provided suitable sites for attachment of both species of algae; broken spine tips were preferred by E. compressa . This study showed that these algae preferred hard substrata, with no scales for attachment. E. compressa appeared earlier and grew faster. The condition of the fish was normal.     

A new species of Sprostoniella Bychowsky and Nagibina, 1967 (Monogenea: Capsalidae) from Chaetodipterus zonatus (Osteichthyes: Ephippidae) in Chamela Bay, Mexico

A new species of Sprostoniella is described from the gills of Chaetodipterus zonatus in Chamela Bay, on the west coast of Mexico. The new species differs from the 2 previously described congeners by having smaller testes each of which is not nearly as long as the ovary. It further differs from the type species, Sprostoniella multitestis, by having a poorly developed pair of accessory sclerites and the cecal diverticula are not confluent posteriorly. The new species also differs from Sprostoniella micrancyra, the other species of the genus, by having a shorter peduncle, the glands of Goto are smaller than the testes and ovary, and by having a slightly different haptoral structure, with 1 pair of hamuli rather than 2 pairs, and 1 central haptoral loculus instead of 2 loculi.     

Origin and evolution of the hamuli in the monogeneans

The hypothesis of the origin and evolution of the hamuli in monogeneans is proposed. It is suggested that the hamuli originated as the adult attachment organs of protomonogeneans inhabited the gills of the first vertebrates. Primarily they were represented by two lateral pairs of large hooks disposed anterior to the larval haptor. The fundamental direction in the evolution of monogeneans was the concentration of all attachment structures on the growing haptor. It the course of this evolutionary process, the hamuli onchoblasts migrated to the haptor, in which they had reached the position in the hind part of the haptor. The neotenic evolution of the Dactylogyridea and Gyrodactyloidea resulted in the forming new hamuli pairs. The hooks of opposite sides of the haptor are joined in a single complex within each side by the transverse plates (bars). So the presence of 4 hamuli is plesiomorphy for all the monogeneans and the presence of the transverse bars and new hamuli pairs are apomorphy for the Dactylogyridea and Gyrodactyloidea, whose evolution was linked with that of the Teleostei. The origin of the new hamuli pairs and transverse bars in the Dactylogyridea and Gyrodactyloidea appears to be a convergence.     

Comments on the mechanism of attachment in species of the monogenean genus Gyrodactylus

Abstract. In species of the monogenean helminth Gyrodactylus , the opisthaptor is the main organ of attachment to the host. The opisthaptor comprises two large centrally positioned hooks or hamuli and sixteen peripherally distributed marginal hooks. This paper describes the functional morphology and the mechanism and sequence of attachment in this species. Information on the attachment process was gathered from observations of live gyrodactylids, from transmission electron microscopy, from scanning electron microscopy of skeletal elements, and by histochemical and X-ray elemental analysis of hook chemical composition. The marginal hooks provide the principal force of attachment whilst the hamuli are not actively employed in the process of attachment. Instead, the hamuli provide a system preventing accidental dislodgement and assist the action of the marginal hooks. Attachment is achieved by the alternating action of two systems of muscles attached respectively to the hamuli and to the marginal hooks. Relaxation or contraction of the muscles connected to the hamuli manoeuvres the hamuli over the extremities of the accessory ventral bar and allows them to pivot around their longitudinal axis, effectively raising or lowering the opisthaptoral dome. Under reduced opisthaptoral tension, the independent gaffing activity of the marginal hooks ensures a secure attachment to the host's epidermis. Repositioning of the hamuli then raises the opisthaptoral dome to tension the peripheral marginal hooks. The sequence of attachment is complete when all the muscles associated with the hooks are in a state of relaxation but are held securely and under tension by the surrounding, stretched, opisthaptoral dome.