The effect of cat Felis catus predation on three breeding Procellariidae species on Marion Island

Breeding success of Pterodroma macroptera, Procellaria aequinoctialis and Pachyptila vittata salvini in three cat-free and three control areas were used to evaluate the effects of cat Felis catus predation on the avifauna of Marion Island. Breeding success of all three species was significantly higher in the combined cat-free areas than in the combined control areas. However, breeding success in one cat-free area failed to show a significant difference from its particular control area, probably as a result of higher skua (Catharacta antarctica) predation inside the cat-free area. Chicks of P. macroptera and P. aequinoctialis were especially vulnerable to cat predation, since cats can enter their nesting burrows. P. macroptera was seriously affected by cat predation because it is the most abundant of only two winter-breeding petrels. Significant changes in the number of nest visits by these petrels during their breeding season followed hatching dates, which in turn were concomitant with, or were followed by significant differences in the combined breeding success between the cat-free and control areas. The cat-free areas show that an elimination of cat predation would still favour the recovery of the petrel population.     

Inshore occurrence of southern right whales (Eubalaena australis ) at Subantarctic Marion Island

Opportunistic shore-based sightings of southern right whales Eubalaena australis for Marion Island (46°54’S, 37°45’E) were documented at five different times between 1974 and 2009. Whales were sighted between May and September and exclusively on the eastern lee side of the Island. Notwithstanding some observer biases over this time frame, the species appears to be an infrequent visitor to the inshore marine environment of Marion Island.     

Diet of the blue petrel at sub-Antarctic Marion Island

Food samples were collected from 49 blue petrels Halobaena caerulea at Marion Island in the sub-Antarctic region. These were analysed and the results compared with previously published data collected at other islands. Crustaceans formed the major prey by mass (59,5%) and frequency (100%), with Euphausia vallentini being of particular importance (56,6% by mass of Crustacea). Other prey included fish, cephalopods and two species of insects, a moth (Noctuidae) and an assassin bug Nabis.     

Feeding ecology of major carnivorous fish from four eastern Cape estuaries

Stomach content analyses were performed on eight carnivorous fish from four eastern Cape estuaries. Dietary importance was assessed by using three unrelated methods and by combining them to determine the index of relative importance of each food item. It was attempted to relate the percentage of fish with food in the stomach and the feeding intensity to the abundance of the fish in a particular estuary. In general fish consumed more food in estuaries where they were more abundant. The few exceptions that occurred could indicate that a particular estuary was selected for purposes other than food availability eg. Tachysurus feliceps in the Krom estuary for spawning grounds or because of inter- or intraspecific competition for food eg. T. feliceps and Monodactylus falciform is in the Krom and Argyrosomus hololepidotus in the Gamtoos and Sundays estuaries. Similarity analyses showed resource partitioning. Predators such as A. hololepidotus, Elops machnata, Lichia amia and Platycephalus indicus preferred teleost fishes such as mullets and Gilchristella aestuarius, whereas the stomach content of Pomadasys commersonnl, T. feliceps and M. falciform is were dominated by Crustacea, particularly Upogebia africana. Most estuarine predators showed a diverse prey selection, but the food web was characterized by a high energy flow per pathway.     

Annual cycle of the southern elephant seal Mirounga leonina (Linn.) at Marion Island

The annual cycle of southern elephant seals, Mirounga leonina, was studied at Marion Island (46°54'S, 37°45' E), between August 1973 and December 1976. Data on the breeding and moulting haul-out of different age and sex classes were obtained by conducting once weekly censuses in a selected study area. The haul-out sequence, characterized by a high degree of synchronization and annual regularity was similar to that occurring at other breeding grounds. Photoperiod, in particular the mean monthly increase in day length, appeared to act as an obligatory proximate factor initiating the haul-out to breed and onset of hair growth. Temperature and radiation appeared to act as obligatory ultimate factors initiating the haul-out to moult.     

Length/mass relationships,energetic content and the otoliths of Antarctic cod Paranotothenia magellanica (Nototheniidae: Pisces) at sub-Antarctic Marion Island

Relationships between otolith length and fish length, wet and dry mass and total energy are described for Antarctic cod Paranotothenia magellanica from Marion Island (sub-Antarctic Indian Ocean). The relationships were all highly significant and allow for more detailed and quantitative studies of the trophic structure of the area     

The anaesthetic potency of benzocaine-hydrochloride in three freshwater fish species

Anaesthesia was induced in the common carp, Cyprinus carpio, tiiapia, Oreochromis mossambicus and rainbow trout, Salmo gairdneri, at concentrations of 25; 50; 75 and 100 mg/1 of benzocaine-hydrochloride as well as neutralized benzocaine-hydrochloride at water temperatures of 15; 20 and 25 °C. The results obtained indicated intra-and interspecific differences in the susceptibility of fish to anaesthesia due to metabolic, chemoreceptive and temperature tolerance differences in and amongst the three species.     

Mycobacterium fortuitum isolated from three species of fish in South Africa

Mycobacterium fortuitum was isolated from 3 species of freshwater fish in South Africa for the first time. The bacterium was isolated from oscars, guppies and discus fish from different sources. Heavy mortalities as a result of infection with this bacterium were reported from a guppy farm and the multi-resistance of this isolate to antimicrobials rules out the treatment of infected fish.     

Feeding ecology of four livestock species under different management in a semi-arid pastoral system in South Africa

The Leliefontein communal area in Namaqualand is grazed by mixed species herds that have multiple benefits for pastoralists. This study assessed how the management (herding and free-ranging) of different livestock herds affects their feeding ecology during the wet and dry seasons in a semi-arid shrubland. By using direct observations of livestock grazing in the field, we established their habitat preferences, diet selection and resources overlap. Results indicate that all free-ranging livestock can be considered grazers with cattle being selective. When sheep are herded, they tend to be more generalist feeders and herded goats are browsers. Livestock diet selection and forage preferences are largely linked to the habitats in which they graze and browse. Dietary overlap is highest between free-ranging livestock irrespective of season, whereas herded livestock are able to consume a food source with little potential competition from other livestock. Although the wet-season annual forage resources are able to sustain the livestock population in Leliefontein, this study concludes that the overdependence on annual vegetation would make livestock vulnerable during drought periods when forage production is low.     

Fluctuations in the Population of Southern Elephant Seals Mirounga Leonina at Kerguelen Island

An analysis of census information published for the years 1952, 1958,1960 and 1970 and that obtained during this study in 1977, indicates that both the breeding bull and cow components of this population fluctuated in numbers during the past 25 years. In spite of these fluctuations, the general trend for the cow component was to increase at a rate of 1,4% per year, while the bull component decreased at a rate of 1,9% per year. An analysis based on subdivisions of the study area into distinct regions indicated that the range of fluctuation increased as mean density increased. The population is regarded as a stable fluctuating population and the influence of environmental and social factors on the observed population trends is discussed.     

Sulfadimethoxine and ormetoprim residues in three species of fish after oral dosing in feed

Nile tilapia Oreochromis niloticus, summer flounder Paralichthys dentatus, and walleyes Sander vitreus were treated with Romet-30 (PHARMAQ AS, Oslo, Norway) via a medicated ration at 50 mg Romet-30 kg fish body weight(- 1) d(-1) for 10 d to compare the elimination kinetics of the test substance. This study was part of a larger effort to develop a species grouping concept for the labeling of therapeutic compounds for cultured fishes. The fish tests were conducted at the ideal water temperature for each species and at 5 degrees C lower than the ideal temperature except for summer flounder, which would not feed at the lower temperature of 15 degrees C. Test temperatures were 30 degrees C and 25 degrees C for Nile tilapia, 20 degrees C and 17 degrees C for summer flounder, and 25 degrees C and 20 degrees C for walleyes. Neither component of Romet-30 (sulfadimethoxine and ormetoprim) could be detected in samples of the edible portion of walleyes (muscle plus skin) collected at day 10 posttreatment or thereafter. In studies with summer flounder, only one fish had a detectable concentration of either component on day 21 or thereafter. Elimination of Romet-30 by Nile tilapia was extremely rapid. The limited number of Nile tilapia with detectable sulfadimethoxine or ormetoprim during the posttreatment period prevented the determination of elimination half-life or elimination in this species.     

Comparative behaviour and ecology of two sympatric mongoose species (Cynictis penicillata and Galerella pulverulenta)

The activity, movements, home range size, habitat selection, social structure, density, pattern of faeces deposition, anti-predator behaviour, diet, and availability and distribution of the main food sources of two mongoose species [the yellow mongoose Cynictis penicillata and the Cape grey mongoose Gaierelia pulverulenta (= Herpestes pulverulentos) in a coastal area of South Africa are compared, Both species were diurnal. Galerella did not use dens, whereas Cynictis never rested outside a den. Total distance moved, home range size and density did not differ between the two species. Galerella frequented bush, whereas Cynictis frequented open fields. The yellow mongoose was more social than the grey mongoose, but the basic social structure was similar. Faeces of Cynictis were found in large clumps close to the dens, while those of Galerella were more scattered. This parallels the greater constancy of use of the sleeping sites by Cynictis. Rodents (> 90% of Cape grey mongoose diet) were much more abundant in the bush, while availability of insects (main food source for the yellow mongoose) was higher in the open fields. Habitat selection, Ihrough its effects on anti-predator and feeding strategies, might have been the leading factor in the evolution of sociality in herpestids.     

Prevalence and risk factors for Campylobacter spp. in chicken broiler flocks in Reunion Island (Indian Ocean)

Our objectives were to determine Campylobacter prevalence in broiler chicken flocks in Reunion Island and to define specific practices associated with the presence of Campylobacter spp. Infection in Reunionese broiler flocks. Fifty broiler flocks were studied in Reunion Island from May 2007 to February 2009. A questionnaire was submitted to the farmers and samples of fresh droppings were collected to assess the flock's Campylobacter status. Fifty four percent of the flocks were infected by Campylobacter spp.: 30% (95% CI: 28.71-31.29) were infected with Campylobacter coli and 17% (95% CI: 15.95-18.05) with Campylobacter jejuni; only 7% (95% CI: 6.28-7.72) were infected by both species at the same time. Several poultry houses in the farm (OR=11.2; [1.05-92]) and cleaning without any detergent (OR=13.1; [2.1-78.3]) increased the risk of Campylobacter infection. A distance higher than 500 m between broiler farms (OR=0.27; [0.1-0.8]) and use of disinfectant during the rearing period decreased this risk of infection (OR=0.15; [0.1-0.75]).     

>Utilization of shallow subtidal bays associated with warm temperate rocky shores by the late-stage larvae of some inshore fish species,South Africa

>This work describes the utilization of shallow, subtidal bays, associated with rocky shores, by the late-stage larvae and early juveniles of some common inshore fishes. Larval and early juvenile fishes were collected in seven small bays (30–50 m wide) between Port Alfred (33°36’S, 26°53’E) and Hamburg (33°17’S, 27°29’E), using a modified, beach seine net (500 µm mesh). Four bays were sampled weekly during peak fish spawning (September–November 2004) to firstly assess whether larval fishes occur in these previously-unstudiedhabitats and secondly, to assess the extent of this utilization in terms of species occurrence, abundance and potential nursery function. An additional three replicate bays, situated >50 km away near Bira were used for comparison. In total, 14 fish families represented by 26 taxa were recorded but the catch was dominated by a small suite of common species. Bays were extensively utilized by Sparidae (>Diplodus capensis >and >Sarpa salpa>), and to a lesser extent by Clinidae (>Clinus superciliosus>), Mugilidae (>Liza >spp.) and Kyphosidae (>Neoscorpis lithophilus>). Mean CPUE of larvae was high and exceeded 900 individuals per seine haul. Larval abundance peaked at 4000 larvae per haul and at these times, was dominated only by the two sparid species. Abundance of sparid larvae exceeds that recorded for these species in surf zones, estuaries or the shallow nearshore habitatssampled to date in temperate South Africa by an order of magnitude. Larval abundance was significantly higher during new moon sampling throughout the study period, but was not significantly different between repeated samples collected per site on each fieldtrip. The length-frequency of larvae utilizing the bays was dominated by postflexion stages ranging 7–14 mm SL. Length-frequency distribution of >Diplodus, Sarpa, Clinus, Sparodon, Neoscorpis >was indicativeof grow-out and use of bays as interim nurseries. The nursery function of these bays is supported by gut analysis of a sub-sample of the dominant species, >Diplodus capensis, >which showed that these larvae were actively feeding in the area, predominantly on copepods. This work prompts further research on shallow habitats associated with rocky shores particularly the shelter and feeding role that these under-studied habitats are playing in the early life history of coastal fishes.     

Stereology of the liver in three species of Leontopithecus (Lesson, 1840) Callitrichidae--primates

Studies on liver morphology and stereology are relevant to the comparative anatomical and pathological research. They also facilitate the use of non-human primates in basic research, which has substantially supported studies in human medicine. Quantitative studies of liver structures have also been more extensive in Old World primates and other vertebrates. Twenty-three livers of adult lion tamarins were studied (six Leontopithecus rosalia, seven Leontopithecus chrysomelas, and 10 Leontopithecus chrysopygus), dissected, and fixed in 10% neutral buffered formalin solution. For stereological quantification, the liver was regarded as consisting of parenchyma (hepatocytes) and stroma (non-hepatocytes). The volume density (V(v)) was determined by point counting, and the disector method was used to obtain the numerical density of hepatocytes (N(v)). Hepatic stereological differences among the three species of lion tamarins were not statistically significant. Therefore, the pooled V(v[hepatocyte]) and V(v[stroma]) could be determined as 96.2 and 7.4%, respectively, and N(v[hepatocyte]) as 500.33 x 10(6) cm(-3). Significantly different, the values found for V(v[hepatocyte]) and N(v[hepatocyte]) in lion tamarins were, respectively, 0.09 and 2.8 times greater than those in baboons, and 0.17 and 3.8 times greater than those in man. However, the V(v[stroma]) was 1.04 times smaller than that in baboons and 1.79 times smaller than that in man.     

Three new Chromadoropsis species (Nematoda,Desmodoridae) from Southern Africa and the North Sea

Three new Chromadoropsis species with four pharyngeal bulbi are described from Southern Africa, Namibia (S.W.A.) and the North Sea. C. granulosus sp.nov. is described from a sandy beach near Port Elizabeth. This species is characterized by a very distinct layer of yellow granules just below the cuticle. C. namibiensis sp.nov. is described from a sandy beach at Langstrand, Namibia. This species can be distinguished by the length and shape of the gubernaculum and spicules as well as the size of the capitulum. C. longispiculosa sp.nov. is described from the North Sea and is characterized by the long spicules and the presence of numerous porids. The genus Chromadoropsis Filipjev, 1918 is revised.     

3种早熟禾苗期的短期抗旱性研究

采用盆栽试验,在苗期进行水分胁迫下,对青海扁茎早熟禾Poa pratensisvar.anceps cv. Qinghai、波伐早熟禾P.poophangorum和巴润早熟禾P.pratensiscv.Baron相对含水量、电导率、游离脯氨酸含量和丙二醛含量变化进行了研究。结果表明,3种早熟禾的相对含水量随水分胁迫时间的延长呈下降趋势,而相对电导率、游离脯氨酸和丙二醛含量均呈增加趋势。综合分析认为,3种早熟禾苗期抗旱性强弱为青海扁茎早熟禾>巴润早熟禾>波伐早熟禾。     

Internal parasites of possums (Trichosurus vulpecula) from Kawau Island, Chatham Island and Stewart Island

As part of a search for pathogens that might be useful agents for biological control of possums, the three largest offshore islands of New Zealand that still have possums were surveyed to determine the pathogens present in these isolated populations. Brushtail possums from Kawau Island (n = 158), Chatham Island (n = 214) and Stewart Island (n = 194) were examined for internal parasites. Possums from Kawau Island were infected with Eimeria spp. (16.7%), Bertiella trichosuri (5.2%) and Purustrongyloides trichosuri (15.5%). No Paraustrostrongylus trichosuri or Trichostrongylus spp. were found. Possums from Chatham Island were infected with Eimeria spp. (10.9%). Bertiella trichosuri (3.6%), T colubriformis (6.6%), T retortaeformis (1%) and T. vitrinus (0.5%). No Parastrongyloides or Paraustrostrongylus spp. were found. Possums from Stewart Island were infected only with Eimeria spp. (4.6%). Because of their paucity of some parasites, the opportunity exists to use these offshore islands to study the introduction and spread of a parasite into a possum population, and what technology would be required to bring it to hyperendemicity.