Sarcocystosis among Wild Captive and Zoo Animals in Malaysia

Sarcocystis sp. infection was investigated in 20 necropsied captive wild mammals and 20 birds in 2 petting zoos in Malaysia. The gross post-mortem lesions in mammals showed marbling of the liver with uniform congestion of the intestine, and for birds, there was atrophy of the sternal muscles with hemorrhage and edema of the lungs in 2 birds. Naked eye examination was used for detection of macroscopic sarcocysts, and muscle squash for microscopic type. Only microscopically visible cysts were detected in 8 animals and species identification was not possible. Histological examination of the sections of infected skeletal muscles showed more than 5 sarcocysts in each specimen. No leukocytic infiltration was seen in affected organs. The shape of the cysts was elongated or circular, and the mean size reached 254 × 24.5 µm and the thickness of the wall up to 2.5 µm. Two stages were recognized in the cysts, the peripheral metrocytes and large numbers of crescent shaped merozoites. Out of 40 animals examined, 3 mammals and 5 birds were positive (20%). The infection rate was 15% and 25% in mammals and birds, respectively. Regarding the organs, the infection rate was 50% in the skeletal muscles followed by tongue and heart (37.5%), diaphragm (25%), and esophagus (12.5%). Further ultrastructural studies are required to identify the species of Sarcocystis that infect captive wild animals and their possible role in zoonosis.     

Sexually distinct development of vocal pathways in Xenopus laevis

Deterministic rules, rather than experience, are thought to regulate the development of simple behaviors in vertebrates and invertebrates. We revisited this issue through examination of the sexually distinct vocalizations of African clawed frogs (Xenopus laevis), a reproductive behavior used by sexually mature males and females. We discovered that, as expected for simple behavior, female vocalizations develop through deterministic rules. The rare calls of juvenile females are indistinguishable from those of adult females. The vocal pathways of juvenile females, as measured by the contractile properties of the laryngeal muscles (the vocal muscles) and the laryngeal motoneuron somata (vocal motoneurons) size, are the developmental default and do not differentiate as they mature. Male Xenopus, in contrast, produce extensive vocalizations with rudimentary acoustic structure before reaching sexual maturity. Moreover, the functional properties of the vocal central pattern generator mature before muscle fibers and motoneuron size are fully masculinized. The results suggest that neuronal activity during development may be important in organizing the contractile properties of the muscle fibers in male, but not in female Xenopus. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 862–874, 2010     

Molecular phylogeny of Sarcocystis fayeri (Apicomplexa: Sarcocystidae) from the domestic horse Equus caballus based on 18S rRNA gene sequences and its prevalence

Sarcocystosis is a parasitic disease caused by an intracellular protozoan parasite Sarcocystis belonging to the phylum Apicomplexa. These parasites have a requisite two-host life cycle. Recently, there are many Sarcocystis species that identified morphologically. In the present study, diaphragmatic muscle samples from the domestic horse (Equus caballus) were examined for Sarcocystis infection. The natural infection with sarcocysts was recorded to be 62·5% for only microcysts in the infected muscles. Molecular analysis using the 18S rRNA gene was conducted to swiftly and accurately identify the recovered species. Studies on the expression of the 18S rRNA gene have confirmed that the present parasite isolates belong to the Sarcocystis genus. The sequence data showed significant identities (>80%) with archived gene sequences from species within the Sarcocystidae family, and a dendrogram showing the phylogenetic relationship was constructed. The most closely related species were the previously described Sarcocystis fayeri and Sarcocystis bertrami. The current data showed that the present species was identified as S. fayeri and deposited in GenBank (accession number MF614956.1). This study highlights the importance of the genetic data in the exact taxonomy within sarcocystid species.     

Gonad Morphology, Colony Demography and Evidence for Hermaphroditism in Gobiodon Okinawae (Teleostei, Gobiidae)

Gobiodon okinawae is a small-sized, obligate coral-dwelling goby. The majority of species in this Indo-Pacific genus exhibit an obligatory association with branching live corals and a number have been shown to be bi-directional hermaphrodites in which adults have the capacity to shift between male and female function. Gonadal histology in G. okinawae demonstrated that all individuals had either an ovotestis or an ovary. Some females had an ovary with vitellogenic oocytes, indicating adult female function. Hermaphrodites having an ovotestis were either functionally male, as evidenced by the presence of spermatozoa or, in one instance, functionally female so judged by the presence of vitellogenic oocytes. No individuals were found to have mature gametes of both sexes, although a number of hermaphrodites had an inactive ovotestis with no mature gametes of either sex. Based on size ranges for fish having different gonad morphologies, individuals in this species appear to develop first as a female. They then either mature and function solely as a female, or become hermaphroditic. Findings based on experimentally maintained individuals suggests that adult hermaphrodites can shift sexual function in either direction. Accessory gonadal structures (AGS) were found in both sexes. These consisted of two fully differentiated pairs of lobes, each compartmentalized internally by lumina and containing PAS+secretions. The secretions of the dorsally located AGS were colloidal while those of the ventrally located AGS were fibrillar and granular in nature. The presence of two sets of AGS among males appears to be characteristic of both Gobiodon and its putative sister genus, Paragobiodon. However, the occurrence of fully developed AGS in both females and males has not previously been reported and may be unique to G. okinawae.     

Molecular characterization of Sarcocystis spp. in seabirds from southern Brazil

Sarcocystis spp. are cyst forming apicomplexan parasites that infect many vertebrates including birds. Sarcocystis spp. infection was investigated in tissue samples (pectoral muscles, heart, and brain) of 47 dead seabirds collected from the coastline of Santa Catarina State SC – Brazil, between August 2019 and March 2020. A portion of each tissue was fixed in 10% buffered formalin for histopathologic analysis while DNA was extracted from another portion and screened using nested-PCR targeting ITS1. Based on molecular analysis, Sarcocystis spp. were identified in 15/47 (31.9%) seabirds of five species, kelp gull (Larus dominicanus), manx shearwater (Puffinus puffinus), neotropic cormorant (Phalacrocorax brasilianus), brown booby (Sula leucogaster) and great skua (Stercorarius skua). Microscopically visible sarcocysts were observed only in the pectoral muscle of four seabirds 8.5% (4/47), while in one brown booby, sarcocysts were seen in both pectoral and cardiac muscles. Two types of sarcocysts, thin walled (≤1 μm) and thick-walled (≥ 2 μm) were identified. Based on ITS1 sequence comparison, S. halieti, S. falcatula and three not yet described Sarcocystis spp. were detected. Phylogenetically, S. falcatula isolates were classified as two distinct clusters. This is the first confirmation of S. halieti in seabird's species in South America and S. falcatula in birds of the order Charadriiformes. Further molecular studies are needed to understand the epidemiology of the Sarcocystis spp. infection and its impact on the health of seabirds.     

Blood and Tissue Protozoa of the English Sparrow (Passer domesticus domesticus) in Galveston,Texas*

SYNOPSIS. The 42% incidence of Plasmodium in blood films of English sparrows reported here is the highest on record for surveys of blood parasites of birds in the United States. The only Plasmodium species identified in the sparrows was P. relictum. Adult birds were almost universally infected and tended to experience the highest degree of parasitemia in the spring months, while young birds had a higher blood positivity in the summer months. The lowest incidence of Plasmodium positive blood films occurred in fall and winter in the Galveston area. Overwintering birds had a decrease in parasitemia corresponding to reported minimal gonadal activity in sparrows. The 20% incidence of Lankesterella (avian Toxoplasma) in the blood of these sparrows was also higher than has been reported in other blood film surveys in this country. Incidence of this parasite in blood films was highest in the summer months, corresponding with highest average temperature for the year. Lankesterella could be found in 95% of sparrows whose tissues were examined after autopsy. Ducks and pigeons in the immediate vicinity of the survey sparrows had neither Plasmodium nor Lankesterella in blood films. Resident wild birds from adjacent rural areas, including redwinged blackbirds, boat-tailed grackles, laughing gulls and meadowlarks, had fewer Plasmodium and Lankesterella than the sparrows. A few Lankesterella were found in the liver or spleen of young redwinged blackbirds, and only 2 of 79 wild birds had the organisms in their heart blood. Plasmodium was found only in meadowlarks and included P. hexamerium and elongatum as well as relictum.     

Sexual dimorphism of drumming muscles in European hake (<Emphasis Type="Italic">Merluccius merluccius</Emphasis>)

Dissections of mature and non-mature European hake males and females (N = 142) collected in waters off the western coast of Norway and in the Bay of Biscay (France) in 2004–2006 demonstrate for the first time that this gadoid species contains drumming muscles. There were differences in drumming muscles weight with body length, sex and maturity stage. This study shows that the difference between females and males is primarily manifested during the spawning season, seen both in the French and Norwegian samples. For the mature females the drumming muscles dry weight increases only slightly, if at all, with increase in total length. For mature males there is a corresponding rapid increase. There does not seem to be any consistent difference between the average dry weight of the drumming muscles in immature male and immature and mature female hake of the same length, tested on the Norwegian samples. Our results suggest that male hake, like the males of other gadoids studied, may produce sounds in the context of spawning.     

Factors affecting <Emphasis Type="Italic">Sarcocystis</Emphasis> infection of rats on small tropical islands

The purpose of our research was to explore the limits of rat-python-Sarcocystis distribution among rats on the offshore tropical islands of Singapore, and to examine the effect of island size, insular isolation, landscape peculiarities and anthropogenic disturbance. Commensal rats (Rattus rattus) inhabited all of these islands, regardless of the islands size, proximity to the mainland, biogeographic features, and/or degree of anthropogenic interference. Rats caught on Sakijang Pelepah Island had well deliminated white bellies that are similar to those of sylvatic or feral rats. The prevalence of Sarcocystis spp. on individual islands ranged from 57 to 100%. This is consistent with the range found in forested habitats on Singapore Island. It also exhibited a similar diversity to Sarcocystis spp. and the predominance of Sarcocystis singaporensis. On Sakijang Pelepah Island, one rat (white bellied) was exceptionally heavily infected with both Sarcocystis villivilosi and Sarcocystis sulawesiensis. The muscles of the rats from nearly all of the islands contained immature sarcocysts, which implies that active transmission is taking place on these islands. This suggests that reticulated pythons (Python reticulatus), which are the definitive hosts of rat Sarcocystis, might have been established or frequented in all the islands of Singapore. Our study shows that the Sarcocystis infection load of the rats was negatively correlated with human disturbance, hinting that human disturbance restricts the pythons mobility and thus, reduces infection of Sarcocytis in the islands rats.     

Grouping and Inhibition of Oogenesis in Two Strains of Acanthoscelides obtectus Say (Coleoptera Bruchidae) of Different Geographical Origin-Specificity of This Inhibitory Effect

Summary

Reproduction of A. obtectus females originating from Rubona (Rwanda) was inhibited after grouping (2 females, or 1 male—1 female). Only a few females produced mature oocytes; vitellogenin was synthesized, released into the haemolymph, but not incorporated into the oocytes. When females produced mature oocytes, their ovarian production was lower than in isolated virgin females. After pairing of a male and a female, 38% of the females mated, but mating under these conditions did not stimulate oogenesis.

Oogenesis of females originating from Tours (France) was only slightly inhibited by the presence of males or females of the same origin. “France” males and females inhibited the reproduction of “Rwanda” females under grouping conditions. However, “France” females showed only a slight sensitivity to grouping with “Rwanda” bruchids. In the presence of Phaseolus vulgaris seeds, grouping had no effect and all females, whatever their origin, produced mature oocytes. Inhibition weis relatively specific as cohabitation with bruchids of other genera (Callosobruchus maculatus-Zabrotes subfasciatus) had no effect. Cohabitation with two species of the same genus (Acanthoscelides obvelatus—A. argilaceus) inhibited oogenesis of A. obtectus “Rwanda” strain. The significance of this regulation and its importance in the maintenance of populations in nature are also analyzed.     

Bovine sarcocystosis: Sarcocystis species,diagnosis, prevalence,economic and public health considerations,and association of Sarcocystis species with eosinophilic myositis in cattle

Infections by Sarcocystis in cattle are ubiquitous worldwide. There is considerable debate concerning the identity of Sarcocystis spp. in cattle. Proper diagnosis of Sarcocystis spp. is important to assess their economic and public health importance. Currently there are seven named species: Sarcocystis hirsuta, Sarcocystis cruzi, Sarcocystis hominis, Sarcocystis bovifelis, arcocystis heydorni, Sarcocystis bovini and Sarcocystis rommeli. Additionally, there are unnamed Sarcocystis spp. Two species, S. hominis and S. heydorni, are zoonotic. One out of seven species (S. hirsuta, contracted from cats) forms macroscopic cysts which can be visible during carcass inspection. Current molecular characterization is based on DNA extracted from sarcocysts from naturally infected cattle because DNA was not characterized from tissues of experimentally infected cattle or feces of experimentally infected definitive hosts. Sarcocystis cruzi (transmitted via canids) is recognized as the most pathogenic species and it causes abortion, low milk yield, poor body growth, and outbreaks of clinical sarcocystosis and death. Additionally, Sarcocystis infections have been linked to an inflammatory condition of striated muscles termed bovine eosinophilic myositis (BEM). Cattle affected by BEM appear clinically normal. Diagnosis of BEM at slaughter occurs when inspecting the carcass surface, or once the carcass has been divided into prime cuts or quarters. Sex and breed have no apparent influence on prevalence of BEM. The condition evidently occurs with equal frequency in steers, cows, and heifers. Virtually all striated muscles can be affected including skeletal muscles, the muscles of the eye, larynx, and the heart. In the USA, regulations require condemnation of BEM-affected parts, or (in severe cases) the entire carcass. These aesthetic considerations result in economic losses. Cattle experimentally infected with Sarcocystis did not have BEM at slaughter. Here, we review the status of Sarcocystis spp. and BEM in cattle including prevalence, lesions, epidemiology, and association of BEM with different species of Sarcocystis.     

The influence of urine from asymptotic laboratory populations on sexual maturation in prairie deermice

Male and female prairie deermice housed singly from weaning (21 days) until 40 days of age had urine from one of the following sources applied daily to their nostrils: sexually mature laboratory population males or females, and sexually mature breeder males or females from our laboratory colony. Other males and females were treated with water. Records were obtained of the weights of the tests, seminal vesicles and bacula of males and the ovaries and uteri of females at 40 days of age. The major results of this study were as follow: Female urine from sexually mature and inhibited population or isolated mice stimulated the development of the male reproductive organs significantly more than water or male urine. Male urine applied to young males did not differentially affect the weights of their reproductive organs compared with water and thus showed no inhibition effects. The reproductive organs of females treated with male urine did not differ significantly in weight from those of females treated with female urine. Females treated with water developed significantly larger uteri than those treated with urine from sexually mature population females (P≤0.02), inhibited population females (P<0.001) and inhibited population males (P<0.007).     

White Flank Spots Signal Feeding Dominance in Female Diamond Firetails,Stagonopleura guttata

Plumage colour can be used as an honest signal to convey health and status, which has traditionally been examined in the sexual selection context of choosy females and elaborate males. We use a model avian system to study the role of plumage coloration in a social context such as inter‐ and intrasexual competition over food resources. The diamond firetail (Stagonopleura guttata) is an endemic Australian finch: females have more white flank spots than males, and white spot number was correlated with cell‐mediated immune response in females. We use two experimental designs to test the role of white flank spots for feeding dominance and dominance discrimination in a group‐living bird. The results from two‐choice trials and from single‐arena trials showed that female ornamentation was consistently important in social food contests, and males consistently responded to female spot number. Females with higher spot number fed first, in trials with males and/or females. Also, females preferred to feed next to test birds with low spot number, but males showed no preference for feeding next to birds with few or many spots. Finally, latency to feed was predicted by spot number: both males and females had longer latency to feed if test birds had more spots than the focal birds. We conclude that female, but not male, ornamentation was important for inter‐ and intrasexual food competition. This is one of the very few studies to show that the same plumage ornament can have a different function between the sexes as a signal of social status. Moreover, this study shows that white plumage can be a signal of dominance.     

Ultrastructure of the cyst wall of Sarcocystis spp. from some rodents in Malaysia.

The cyst wall of Sarcocystis cysts from the skeletal muscles and subcutaneous tissues of 4 species of rats and 1 species of bandicoot in Malaysia was examined under the electron microscope. Three types of sarcosysts with morphologically distinct cyst walls were found in these rodents. These morphologically distinct types of sarcocysts occurred as single or mixed infections in their various rodent hosts, suggesting that these rodents are important, though non-specific, intermediate hosts in the life cycle of at least 3 species of Sarcocystis. The final hosts of these Sarcocystis species are unknown.     

Sarcocystis and Its Complications in Camels (Camelus dromedarius) of Eastern Provinces of Iran

The prevalence of Sarcocystis spp. was investigated by gross and histopathological examinations in 250 camels (Camelus dromedarius) slaughtered from 2002 to 2005 in the Mashhad Slaughterhouse, eastern Iran. Samples were taken from the diaphragm, heart, tongue, esophagus and masseter muscles for histopathological studies. No macroscopic sarcocysts were found in the samples at gross inspection. Sarcocysts were detected in 209 of 250 (83.6%) examined camels at histopathological level. The infection rate of the esophagus, heart, masseter muscles, diaphragm, and tongue was 58.8%, 48.0%, 46.8%, 41.6%, and 28.0%, respectively. There was no significant difference in the rate of infection between male (85.8%) and female (81.0%) camels. The tissue response to vital cysts was minimal; however, reaction to the degenerating cysts was severe and caused tissue damages resulting in hyperemia, hemorrhages, mononuclear cell infiltration, necrotic changes, and fibrosis. The wild and domestic carnivores especially dogs may be the final hosts of Sarcocystis spp. in this area.     

ECOLOGICAL ASPECTS OF SEX EXPRESSION IN SUBDIOECIOUS SCHIEDEA GLOBOSA (CARYOPHYLLACEAE)

The importance of ecological factors such as sex lability, spatial segregation, and resource allocation in the evolution of dioecy were examined in Schiedea globosa. S. globosa is a subdioecious species with equal numbers of plants possessing strictly male or female function and a small proportion of hermaphrodites. The propensity for labile sex expression was under both environmental and genetic control; some plants with male function became hermaphroditic (by producing female flowers) under better growing conditions in the field and in the greenhouse. There was some spatial segregation of the sexes. Because of sex lability, more hermaphrodites than males occurred on moister slopes. Although there were not measurable sex-related differences in mortality within or between two flowering seasons, more females than males and hermaphrodites occurred at the bottom of slopes. Males and females produced the same number of ramets and inflorescences, but females had a greater number of flowers per inflorescence. Males and females had the same number of ovules (vestigial in males), but females had larger ovules and longer stigmas. Hermaphrodites and males had the same amount of pollen per flower despite the production of fruit by the hermaphrodites. In hermaphrodites, there was no apparent tradeoff within flowers between pollen production and ovule production. These results indicate that spatial segregation, sex lability, and environmental conditions influence allocation patterns of S. globosa, and in combination with high inbreeding depression and selling rates, may promote the further evolution of dioecy in S. globosa.     

Reproductive biology of the southern thorny skate Amblyraja doellojuradoi (Chondrichthyes,Rajidae)

The total lengths (L_T) of 193 males (209–556 mm) and 130 females (275–515 mm) of Amblyraja doellojuradoi, a commercial by‐catch species on the Argentinean continental shelf, which are increasingly retained, were analysed. No sexual dimorphism was observed in the L_T at which 50% of individuals were sexually mature; males matured at 448 mm and females at 411 mm, c. 80 and 82% of maximum L_T. The hepato‐somatic index was similar among sexes, but significantly different between maturity stages, being lower in mature than immature specimens. Males had no seasonal difference in the hepato‐somatic index and females had the lowest index in autumn. The gonado‐somatic index was lower in males than in females and significantly higher in mature than immature specimens of both sexes. Males had the highest index in autumn and females had no seasonal difference. Collectively, these results would indicate that A. doellojuradoi breeds in autumn.     

Blinking behavior in great-tailed grackles (Quiscalus mexicanus) increases during simulated rainfall

Animals often adjust their behavior in response to changes in environmental conditions, and these behavioral adjustments may result from sensory constraints. In particular, rainfall influences behavior but our understanding of its effects on visual abilities is limited. This study, therefore, tested the hypothesis that rainfall influences blinking behavior, a major component of visual processing, in captive great-tailed grackles (Quiscalus mexicanus). The blinking behavior of the grackles was recorded when they were exposed to simulated rain that was direct (water falling directly atop them) or indirect (water falling at a distance from them). The grackles exhibited increased blinking behavior when they were exposed to the direct rain but not the indirect rain. These results suggest that rainfall may impact visual processing in birds through sensory impairments.     

Respiration rates of two closely related species of carabids in Australia

Abstract The respiration rates of Notonomus gravis (Chaudoir) and N.philippi (Newman) (Coleoptera: Carabidae) were measured at temperatures between 10°C and 45°C. Mature males of both species had higher respiration rates than mature females. There was no difference between the rates of teneral male and female beetles at 30°C. The difference in respiration rates between the sexes is attributed to the maternal behaviour, and decreased surface activity, of mature females.     

Male‐skewed adult sex ratio,survival, mating opportunity and annual productivity in the Snowy Plover Charadrius alexandrinus

Sex differences in adult mortality may be responsible for male‐skewed adult sex ratios and male‐skewed parental care in some birds. Because a surplus of breeding males has been reported in serially polyandrous populations of Snowy Plover Charadrius alexandrinus, we examined sex ratio, early‐season nesting opportunities, adult survival and annual reproductive success of a Snowy Plover population at Monterey Bay, California. We tested the hypotheses that male adult survival was greater than female survival and that a sex difference in adult survival led to a skewed adult sex ratio, different mating opportunities and different annual productivity between the sexes. Virtually all females left chicks from their first broods to the care of the male and re‐nested with a new mate. As a result, females had time to parent three successful nesting attempts during the lengthy breeding season, whereas males had time for only two successful attempts. Among years, the median population of nesting Plovers was 96 males and 84 females (median difference = 9), resulting in one extra male per eight pairs. The number of potential breeders without mates during the early nesting period each year was higher in males than in females. Adult male survival (0.734 ± 0.028 se) was higher than female survival (0.693 ± 0.030 se) in top‐ranked models. Annually, females parented more successful clutches and fledged more chicks than their first mates of the season. Our results suggest that in C. alexandrinus a sex difference in adult survival results in a male‐skewed sex ratio, which creates more nesting opportunities and greater annual productivity for females than for males.     

Influence of honey and maternal age on egg load of lab-cultured <Emphasis Type="Italic">Cotesia marginiventris</Emphasis>

Laboratory experiments were conducted to determine the impact of feeding status and maternal age on egg load of Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae), a solitary, koinobiont endoparasitoid of noctuid pests. Egg load was defined as the number of mature (i.e., fully-chorionated) eggs found in the ovaries and oviducts. Significantly more mature eggs were stored in honey-fed than starved females. For honey-fed females, egg load increased within several days of isolation from hosts. This study suggests that C. marginiventris is weakly synovigenic because females emerge with a considerable number of mature eggs and are capable of maturing many more eggs. Feeding on a suitable source of carbohydrate should increase the egg load (i.e., potential fecundity) of this insect within 3–4 days in an in vivo rearing system.