The valves of the cardiac outflow tract of the starry ray,Raja asterias (Chondrichthyes; Rajiformes): Anatomical,histological and evolutionary aspects

The cardiac outflow tract of chondrichthyans is composed of the myocardial conus arteriosus, equipped with valves at its luminal side, and the bulbus arteriosus devoid of myocardium. Knowledge of the histomorphology of the conal valves is scarce despite their importance in preventing blood backflow to the heart. Current information on the subject refers to a single shark species. The present report is the first to describe the structure of the conal valves of a batoid species, namely, Raja asterias. Hearts from seven starry rays were examined using scanning electron microscopy and histochemical techniques for light microscopy. In all hearts, the conus showed four transverse rows of three pocket‐like valves each. Each valve was composed of a leaflet and its supporting sinus. The leaflet had a stout central body, rich in glycosaminoglycans, which contained fibroblasts, collagen and elastin. The central body was surrounded by two thin fibrous layers, outer and inner, formed mainly by collagen. The valves of the anterior row, which were the largest of the valvular system, were attached proximally to the conus arteriosus and distally to the bulbus arteriosus, and not to the ventral aorta as previously reported for chondrichthyans. The arrangement of the anterior valves in the starry ray is an anatomical pattern that apparently has been preserved throughout the evolution of vertebrates.     

Pseudorhabdosynochus kritskyi n. sp. (Monogenea: Diplectanidae) on Gag from the Gulf of Mexico

Abstract

Pseudorhabdosynochus kritskyi n. sp. from gag Mycteroperca microlepis (Perciformes: Serranidae) of the Gulf of Mexico is described and differs from all known species of the genus by the shape of the vagina. It may be further differentiated from P. americanum, P. amplidiscatum, P. caballeroi, P. epinepheli, P. latesi, P. monaensis, and Cycloplectanum magnisquamodiscum in having fewer rows of scales in each squamodisc. This new species is most similar to P. beverleyburtonae, P. bocquetae, P. cupatum, P. lantauensis, P. melanesiensis, P. querni, P. serrani, P. summanae, P. vagampullum, and Cycloplectanum riouxi in having 15 or fewer squamodisc rows, but it may be separated by differences in either squamodisc morphology or differently shaped hamuli or bars.     

Gross Anatomy of Pampas Deer (Ozotoceros bezoarticus,Linnaeus 1758) Mouth and Pharynx

The aims of this study were to describe the anatomy of the mouth and pharynx of the pampas deer, and to consider its evolutionary feeding niche according to those characteristics. Gross dissections of the mouth and pharynx were performed in 15 animals, 10 adult females and five young animals under 1 year (three males and two females), all dead by causes unrelated to this anatomical region. The upper lip entered in the constitution of a pigmented nasolabial plane. The masseter muscles weighed 43.8 ± 3.5 g and represented 0.23% of body weight, which corresponds to ruminants of feeders intermediate to grazers and browsers. Parotid glands represented 0.08% of the body weight, characteristic that also categorize the pampas deer as belonging to the intermediate feeding group. The dental formula was the same of the domestic ruminants. The upper incisors and canines were absent, and instead of them, there was a dental pad (Pulvinus dentalis). The upper canine teeth were present only in the deciduous dentition. The existence of a brachydont dentition turns Ozotoceros very vulnerable to continuous use as there is no compensatory teeth growth. The particular anatomy of the mouth and lips of this animal was adapted to a very selective feeding, taking highly nutritious sprouts beyond plant category. In conclusion and in addition to previous studies of anatomy of the digestive organs in this species, pampas deer may be categorized as belonging to the intermediate type of feeding.     

Problems presented by geographical variation in the African vine snakes,genus Thelotornis

Analysis of variation in 771 specimens of the genus Thelotornis A. Smith (Colubridae) confirms the absence of intergradation between the taxa kirtlandii (Hallowell) and oatesii (Gunther) in northern Angola and southern Zaire, so 7. capensis A. Smith is accepted as a full species. The western race 7. capensis oatesii shows very little variation, but the eastern populations of 7. capensis are extremely variable and it is convenient to revive the name mossambicanus (Bocage) for the populations which occur from central Mocambique northwards. T. c. oatesii hybridizes extensively with T. c. capensis and 7. c. mossambicanus in southeastern Rhodesia and adjacent Mocambique. Northern populations of 7. c. mossambicanus show features of 7. kirtlandii, but these are apparently primitive characters retained since the original partition of Thelotornis into western and eastern forms. The highlands of Kenya and northern Tanzania isolate these northern mossambicanus from the nearest kirtlandii populations in Uganda.     

A new southern African genus in the holothurian family Cucumariidae (Echinodermata: Holothuroidea) with the recognition of two subspecies in Cucumaria frauenfeldi Ludwig

A new genus Roweia in the holothurian family Cucumariidae is erected to accommodate two southern African dendrochi-rotids, Cucumaria frauenfeldi Ludwig and C. stephensoni John which have previously always been classified in Cucumaria (si). Some intraspecific variations in R. frauenfeldi are discussed and, on this basis, the species is rediagnosed and two subspecies recognized. The species and subspecies of the new genus are keyed, their synonymy is considered and distributions mapped. New information in regard to R. stephensoni is also included.     

Dermatophilus congolensis Infection in Goats in Tanzania

When goats in Eastern Tanzania were screened for skin diseases, Dermatophilus congolensis was isolated from the skin lesions in 8 of 484 animals examined. In one severely affected case, the disease was also characterized by histological studies (Gram stain, Giemsa stain and routine HE studies) and electron microscopy. The histological picture was characterized by hyperkeratosis, parakeratosis, acanthosis, folliculitis and an inflammatory cellular reaction involving the epidermis. Gram stain and Giemsa stain revealed longitudinal and transverse branching filaments in the deeper layers of the epidermis. Ultrastructural studies demonstrated D. congolensis in various morphological forms, ranging from filamentous to tuber-shaped structures, mixed with numerous coccoid bodies of variable size. In some instances, the organisms were geometrically arranged in parallel rows of beading and were present in and among the degenerated epithelial cells. Several host cells showed degenerative changes. Ticks present on the goats were Amblyomma variegatum, Rhipicephalus evertsi, Rhipicephalus pravus and Boophilus sp. The clinical signs, pathological lesions, diagnosis, epidemiology and pathogenesis of the disease are discussed.     

Outbreak of swimmer's itch in Central Italy: Description,causative agent and preventive measures

Swimmer's itch is caused by the penetration of free‐swimming larvae of trematodes of the family Schistosomatidae in human skin. It is usually reported in people engaged in recreational water activities in freshwater bodies and in most of cases, it is provoked by bird schistosomes of the genus Trichobilharzia. In the summer 2017, many cases of dermatitis were recorded in people bathing in the waters of the Albano Lake (Rome, Italy) and a parasitological investigation was carried out in order to ascertain the causative agent of these cases. Snails of the family Lymnaeidae, natural intermediate hosts of bird schistosomes, were collected from lake shallow waters to detect the presence of trematodes of the genus Trichobilharzia. Pools of maximum 10 snails were placed in Petri dishes, and cercarial emergence was stimulated exposing snails to strong artificial light intensity at 25°C. Three hundred and thirty‐seven snails were collected and screened for the shedding of cercariae. Furcocercariae of the family Schistosomatidae, with a morphology overlapping that of the genus Trichobilharzia, were detected in seven Petri dishes. Assuming that in each positive Petri dish just one snail was shedding furcocercariae, the minimum infectious rate was 2.1%. Molecular analysis of furcocercariae allowed ascribing them to the species Trichobilharzia franki. Snails of the species Radix auricularia were identified as intermediate hosts of the parasite. This is the second record of T. franki causing cercarial dermatitis in Central Italy, the third in Italy. The 2017 was in Italy exceptionally warm and dry. Trematodes are sensitive to changes in temperature, being cercarial production and emission rates temperature dependent. Small increases in water temperature would speed up parasite development and transmission, leading to a manifold increase in cercarial emergence. Moreover, high temperatures raise chances to acquire the infection, due to increased time spent in water by people.     

Observations on the Plerocercoid Stage of the Tapeworm Ligula in Three Species of Fish from the Lower Crooked River of Central Oregon

Abstract

Tapeworms in the genus Ligula are cosmopolitan parasites whose plerocercoid stages are found worldwide in fishes of the families Cyprinidae and Catostomidae. Examination of chiselmouth Acrocheilus alutaceus, northern pikeminnow Ptychocheilus oregonensis, and bridgelip sucker Catostomus columbianus revealed the presence of Ligula in the lower Crooked River system of central Oregon. This represents the first report of Ligula intestinalis in two of these host species: chiselmouth and bridgelip sucker. Although most hosts appeared healthy, large external lesions were noted on some bridgelip suckers in close association with a Ligula plerocercoid. The largest plerocercoid recovered was 101.5 cm relaxed length and may represent the longest plerocercoid of Ligula reported from North America.     

The status of some southern African nominal species of Cucumaria (s.e.) referable to a new genus and their ecological isolation

A full history of four nominal species of southern African dendrochirotid holothurians, namely Cucumaria jägeri Lampert, Semperia (= Cucumaria) sykion Lamped, C. insolens Theél and C. sinorbis Cherbonnier, is given and the confusion in their taxonomic status discussed. Morphological differences and habitat selection indicate that the latter three are valid sister species. C. jägeri is relegated to the synonymy of C. sykion, a well-established name which it threatens. Since none of the three species is referable to the genus in which it is currently classified, a new genus Pseudocnella is erected to accommodate them. It is suggested that the Mediterranean Ocnus syracusanus (Grube) be also classified in the new genus. A key to the three southern African species is given, their synonymy detailed, additional notes provided, and the geographic distributions mapped. Although P. sykion and P. sinorbis have an identical geographical range it is demonstrated that the two species are ecologically isolated and thus prevented from any interspecific competition. P. insolens is sympatric with P. sinorbis over a wide area, often occupying the same habitat in a single locality. However, morphological and other evidence points to subtle niche differences between them. A provisional cladogram is proposed to show the possible relationships of the four species included in the new genus.     

New species of the giant deep‐sea isopod genus Bathynomus (Crustacea,Isopoda, Cirolanidae) from Hainan Island,South China Sea

Several specimens of the giant deep‐sea isopod genus Bathynomus were collected by a deep‐sea lander at a depth of 898 m near Hainan Island in the northern South China Sea. After careful examination, this material and the specimens collected from the Gulf of Aden, north‐western Indian Ocean, previously reported as Bathynomus sp., were identified to be the same as a new species to the genus. Bathynomus jamesi sp. nov. can be distinguished from the congeners by: the distal margin of pleotelson with 11 or 13 short straight spines and central spine not bifid; uropodal endopod and exopod with distolateral corner slightly pronounced; clypeus with lateral margins concave; and antennal flagellum extending when extended posteriorly reaches the pereonite 3. In addition, Bathynomus jamesi sp. nov. is also supported by molecular analyses based on mitochondrial COI and 16S rRNA gene sequences. The distribution range of the new species includes the western Pacific and north‐western Indian Ocean.     

Evaluation of the long-term oral consequences of equine exodontia in 50 horses

The aims of this study were to objectively evaluate and quantify the process of post-extraction cheek teeth (CT) dental drift in horses, and to report on associated disorders of CT wear and long-term periodontal health. Fifty horses that had CT oral extraction because of apical infection were prospectively re-examined and a full oral examination, including measurements of some dental parameters, was performed.Narrowing of the extraction space was noted in all cases with complete closure occurring in 18% of horses. The rate of dental drift was calculated as 15.7% of extraction space/year (range 4–50%) and was not associated with the age at extraction (P = 0.78) or frequency of dental care since extraction (P = 0.48). There was a significant negative relationship between the rate of dental drift and the duration of time since extraction (P = 0.008). Overgrowths were present on the opposite CT row in 98% of horses, including opposite the extracted CT and on the Triadan 06s and 11s. No significant difference was noted in either the number of diastemata (P = 0.9) or periodontal disease score (P = 0.8) between the extraction and the contralateral cheek tooth rows.     

A review of equine dental disorders

Equine dentistry is a very important but until recently rather neglected area of equine practice, with many horses suffering from undiagnosed, painful dental disorders. A thorough clinical examination using a full mouth speculum is a pre-requisite to performing any equine dental procedure. Common incisor disorders include: prolonged retention of deciduous incisors, supernumerary incisors and overjet--the latter usually accompanied by cheek teeth (CT) overgrowths. Overjet can be surgically corrected, but perhaps should not be in breeding animals. In younger horses, traumatically fractured incisors with pulpar exposure may survive by laying down tertiary dentine. Loss or maleruption of incisors can cause uneven occlusal wear that can affect mastication. Idiopathic fractures and apical infection of incisors are rare. The main disorder of canine teeth is the development of calculus of the lower canines, and occasionally, developmental displacements and traumatic fractures. The main indications for extraction of "wolf teeth" (Triadan 05s) are the presence of displaced or enlarged wolf teeth, or their presence in the mandible. Developmental abnormalities of the CT include; rostral positioning of the upper CT rows in relation to the lower CT rows--with resultant development of focal overgrowths on the upper 06s and the lower 11s. Displaced CT develop overgrowths on unopposed aspects of the teeth and also develop periodontal disease in the inevitable abnormal spaces (diastemata) that are present between displaced and normal teeth. Diastemata of the CT due to excessive developmental spacing between the CT or to inadequate compression of the CT rows is a common but under diagnosed problem in many horses and causes very painful periodontal disease and quidding. Supernumerary CT mainly occur at the caudal aspect of the CT rows and periodontal disease commonly occurs around these teeth. Eruption disorders of CT include prolonged retention of remnants of deciduous CT ("caps") and vertical impaction of erupting CT that may lead to large eruption cysts and possibly then to apical infections. Disorders of wear, especially enamel overgrowths ("enamel points"), are the main equine dental disorder and are believed to be largely due to the dietary alterations associated with domestication. If untreated, such disorders will eventually lead to more severe CT disorders such as shearmouth and also to widespread periodontal disease. More focal dental overgrowths will develop opposite any CT not in full opposition to their counterpart, e.g., following maleruption of or loss of a CT. Because of the great length of reserve crown in young (hypsodont) CT, apical infections usually cause infection of the supporting bones and depending on the CT involved, cause facial swellings and fistulae and possibly sinusitis. Diagnosis of apical infection requires radiography, and possibly scintigraphy and other advanced imaging techniques in some early cases. When possible, oral extraction of affected CT is advocated, because it reduces the costs and risks of general anaesthesia and has much less post-extraction sequelae than CT repulsion or buccotomy.     

Feeding cluster preferences in four genera of Lories and Lorikeets (Loriinae) that should be considered in the diet of nectarivorous psittacine species in captivity

Lories and lorikeets are popular birds in the pet bird trade, captured from the wild and exported worldwide. Their captive propagation has not been so successful for many species due to health issues, low breeding success and reduced longevity. As a result, uptake from the wild is currently the only way to meet the market’s demand. Field studies on Asian species of loris and lorikeets are limited; therefore, dietary recommendations are based on the well‐studied Australian species such as the rainbow lorikeet (Trichoglossus moluccanus). We aimed to provide an ad libitum diet to diverse Loriinae species at Jurong Bird Park (Singapore) which allowed for them to select between a low and moderate protein diet to compare their nutrient and energy intake with other Loriinae species. We measured the following variables: daily dry matter (DM) intake, nectar‐to‐fruit energy intake ratio (NF ratio), metabolisable energy (ME), protein and non‐protein energy (NPE)‐to‐protein energy (PE) ratio intake (all by kg metabolic body weight MBW, kg^0.75) for 36 pairs over a 1‐month period. A Kruskal–Wallis test revealed every genus had significantly different intakes of DM, NF ratio, NPE‐to‐PE ratio, ME and protein than each other. Post hoc Mann–Whitney U tests confirmed that the majority of variables were ingested in different amounts for each genus except for NF ratio, NPE/PE ratio which Lorius spp. are not different to Charmosyna sp. or Trichoglossus spp. and protein intake of Eos spp. does not differ from Trichoglossus spp. Our conclusion is that no species should be used as a model for a species from another genus of Loriinae; future studies should be species‐specific for each genus to increase captive propagation success.     

Degenerate slave‐makers,but nevertheless slave‐makers? Host worker relatedness in the ant Myrmoxenus kraussei

Socially parasitic ants of the formicoxenine genus Myrmoxenus exhibit considerable diversity in colony structure and life history. While some species are active slave‐makers with many workers and others are workerless ‘murder‐parasites,’ Myrmoxenus kraussei is considered as a ‘degenerate slave‐maker’ because of its very low worker numbers. Here, we document that Temnothorax recedens host workers in single colonies of M. kraussei from Lago di Garda, Italy, exhibit significantly more genetic diversity than workers in unparasitized colonies. This raises the possibility that, despite its low worker numbers, M. kraussei may actively engage in slave raids in nature.     

Prevalence of Yeasts and Mycelial Fungi in Bovine Parasitic Otitis in the State of Minas Gerais,Brazil

Infestations by rhabditiform nematodes and acarids of the genus Raillietia are considered the primary causes of external otitis in cattle in tropical regions. Recently, yeasts of the genus Malassezia have been associated with a relatively high percentage of otitis cases, but the occurrence of other yeasts and mycelial fungi has not yet been reported in the literature. This work studied the presence of fungi in the ear canal of 45 cattle with external parasitic otitis. The results were positive for yeasts of the genus Malassezia in 31 (68.9 %) of the 45 cultures in Mycosel medium supplemented with olive oil. The 45 cultures in Sabouraud dextrose medium revealed the growth of seven (15.5 %) yeasts of the genus Candida, five (11.1 %) Rhodotorulamucilaginosa, two (4.4 %) fungi of the genus Aspergillus and eight ‘Micelia sterilia’. Future studies may confirm and elucidate the importance of these agents in the aetiology of bovine otitis.     

The phyllophorid holothurians of southern Africa with the erection of a new genus

The southern African dendrochirotid holothurians of the family Phyllophoridae (sensu Pawson & Fell, 1965) are revised and a new genus Thyonina is erected to accommodate Thyone articulata Vaney, 1908, which possesses only slender spectacle-shaped rods as body wall deposits. In addition, Thyone proceracorona Cherbonnier, 1952 and T. turrisolida Cherbonnier, 1954, are declared junior subjective synonyms of T. aurea (Quoy & Gaimard, 1833); Havelockia imperfecta Cherbonnier, 1970 is transferred to the genus Thyone, and T. venusta Selenka, 1868 (synonym T. okeni Bell, 1884) is recorded for the first time from southern Africa. These changes bring the total number of phyllophorid holothurians now known from southern Africa to five genera and 11 species. All species are keyed, briefly described and/or discussed, and their local distributions mapped.     

The Genera Rhoptropus and Phelsuma (Reptilia: Gekkonidae) in Southern Africa: A Case of Convergence and a Reconsideration of the Biogeography of Phelsuma

The genus Rhoplropella Hewitt, 1937 is shown to be a junior synonym of Phelsuma Gray, 1825 and the genera Phelsuma and Rhoplropus Peters, 1869 are compared. It is pointed out that Phelsuma ocettata shows a great deal of convergence with Rhoplropus but that both of these forms exhibit their own distinctive derived character combinations. The distribution pattern of Phelsuma on the main-land of Africa and on Madagascar is reviewed inthe light of current theories of biogeography and past continental relationships. It is suggested that the distribution of Phelsuma may represent a track which is also occupied by other reptilian genera.