Isolation,characterization, and in vitro differentiation of ovine amniotic stem cells

Challenge tests with Artemia four different development stages (nauplii, metanauplii, pseudoadults and adults) to white spot syndrome virus was carried out by immersion challenge and virus-phytoplankton adhesion route in order to asses the possibility of Artemia acting as a vector of WSSV to penaeid shrimp Litopenaeus vannamei postlarvae. The WSSV succeeded in infecting four stages Artemia, and nested-PCR detection for WSSV revealed positive results to virus-phytoplankton adhesion route. No mass mortalities were observed in penaeid shrimp postlarvae fed with WSSV-positive Artemia which exposed to WSSV by virus-phytoplankton adhesion route, whereas WSSV DNA detected in penaeid shrimp postlarvae by nested-PCR. By contrary, no WSSV-positive was detected in any animal fed with WSSV-negative Artemia. These results indicated that Artemia could serve as a vector in WSSV transmission.     

Endoparasites of brushtail possums (Trichosurus vulpecula) from the South Island,New Zealand

As part of a study to assess whether endoparasites could assist in the biological control of brushtail possums in New Zealand, we investigated the composition and distribution of possum endoparasites in the South Island. Possums were collected near five of the original release areas in the South Island: Banks Peninsula, Hokitika, Nelson, Dunedin and Invercargill.

Among the nematodes, those most frequently encountered were Trichostrongylus spp., which were present in possums from all five study areas. Trichostrongylus species from possums in the Invercargill area comprised 4.5% T. colubriformis, 0.9% T. vitrinus and 11.3% T. retortaeformis. Paraustrostrongylus trichosuri and Parastrongyloides trichosuri were found only in the Invercargill area, where they infected 1.4% and 14% of possums respectively. The cestode Bertiella trichosuri was present in possums from all locations except Dunedin. The protozoan Eimeria spp. occurred in all areas.

These are the first records of Parastrongyloides trichosuri, Paraustrostrongylus trichosuri, T. vitrinus, T. retortaeformis and Eimeria spp. in South Island possums.

The prevalence of endoparasites and the intensity of infection was very low compared to the lower North Island of New Zealand. Endoparasites at the existing levels in the South Island probably have very little effect on possum populations.     

First record of an introduction of the giant pangasius,Pangasius sanitwongsei Smith 1931, into an African river

A catfish captured in the Breede River (33°56 41.6”S 20°4’45.6”E) in South Africa was identified using morphological and genetic techniques as the giant pangasius, Pangasius sanitwongsei Smith 1931, a new record for South Africa. The wild-caught specimen was a genetic match to juveniles purchased from the pet trade, and most likely originated from a release by an aquarist. Pangasius sanitwongsei is not on the list of fishes currently permitted for import into South Africa, and its presence in the pet trade illustrates the difficulty associated with preventing illegal introductions.     

The histology of the venom-secreting apparatus of the puff-adder,Bitis Arietans

Fish eggs, thought to be those of the liparid fish, Careproctus griseldea, were found In the gill chambers of several specimens of the stone crab, Lithodes tropicalls, caught In deep-water (-600 m) oil the South West African/Namibian coast (-24°46/S/13°28'E). The size class and quantity of crabs involved in this symbiotic relationship are discussed and some observations are made as to the diameter, number and maturity of the fish eggs removed from the crabs.     

Description of a new species of Cordylus Laurenti (Reptilia: Cordylidae) from the south-western Cape,South Africa

A new species of girdled lizard in the Cordylus genus is described from the south-western Cape, South Africa. Unlike other Cordylus taxa the new form usually has only two supraciliaries per side, the posterior parietals are usually separated mesially by a small post-interparietal scale and the lateral body scales are larger than the dorsal scales. The relationships of this new form to other members of the Cordylus group are discussed.     

Plant selection and grazing activity of the invasive snail Theba pisana in coastal Algoa Bay,South Africa

The land snail Theba pisana is a coastal species native to the Mediterranean but has been introduced to regions all over the world, including South Africa and Australia, where it is considered a pest. This study examines the diet of T. pisana and its preference for certain dune plants in the Cape Recife Nature Reserve of Algoa Bay in the Eastern Cape, South Africa. Field observations identified plants being fed on by T. pisana, accounting for almost half of the dune plant species present in the study area. Five plant species, on which snails were found frequently and in high abundance, were selected for feeding preference experiments. Laboratory experiments and field observations indicate that T. pisana feed preferentially on Tetragonia decumbens over Osteospermum moniliferum, Osyris compressa and Cynanchum obtusifolium. It is clear that while T. pisana is reported to have a generalist diet, consuming a range of plant species commonly found in South African dune vegetation, it also exhibits a definite preference for T. decumbens. The reasons for this preference need to be investigated further.     

Diet,dietary selectivity and density of South American grey fox,Lycalopex griseus,in Central Chile

The South American grey fox Lycalopex griseus is a canid widely distributed in southern South America; however, some aspects of its biology are still poorly known. We studied the diet and density of L. griseus in the Lago Peñuelas Biosphere Reserve, in Central Chile. The trophic niche breadth was B = 6.16 (B_sta = 0.47) and prey diversity was H′ = 2.46 (H_max′ = 3.17, J′ = 0.78). The highest proportions of prey consumed in the diet were Oryctolagus cuniculus (52.21%) and other mammals (32.78%). We compared these results with a latitudinal gradient of diet results for this species in Chile. L. griseus eats mostly mammals (>90% of total prey), consuming the rodent Phyllotis darwini and reptiles in the northern zone; Oryctolagus cuniculus, Octodon degus and Abrocoma bennetti in the central zone; Abrothrix spp. and lagomorphs in the southern zone; and Lepus capensis and Ovis aries in the austral zone. The estimated density of L. griseus in Lago Peñuelas NR was 1.3 foxes/km².     

Additional material of the enigmatic golden mole Cryptochloris zyli,with notes on the genus Cryptochloris (Mammalia: Chrysochloridae)

Van Zyl’s golden mole (Cryptochloris zyli) is a distinctive but little-known species from the northwestern Cape Province of South Africa. Many authors have mentioned that it is known only by the holotype. Two other specimens are now known to exist; one was discovered in the Museum of Comparative Zoology at Harvard University, and the other, which has been mentioned in publication but overlooked, is in the Natural History Museum in London. Differentiation of C. zyli from sympatric chrysochlorids, and from its congener C. wintoni, are discussed.     

Observation of Gas Bubble Disease in Postlarvae of Indian Carps Important to Aquaculture

Abstract

Postlarvae of important Indian carps affected with gas bubble disease were observed in a nursery pond located in Bhubaneswar, Orissa State, India. Affected specimens had distended abdomens filled with gas and were observed floating upside down and occasionally exhibiting very slow swimming movements. There was mortality among the most severely affected specimens. Experiments conducted on postlarvae indicated that dissolved oxygen (DO) supersaturation in the pond was not the cause of gas bubble disease. Pond water supersaturatcd with up to 38 mg oxygen/L failed to produce gas bubble disease in the postlarvae. It was observed that, when DO ranged between 4 and 6 mg/L, freshly ingested phytoplankton continued to release oxygen in the bright sunlight, because photosynthesis went on in the more or less translucent bodies of the postlarvae. The mounting pressure and volume of oxygen in the gut impaired digestive function and distended the abdomen, causing the gas bubble condition. Fish with this condition became buoyant and floated upside down. Mortality was probably caused by gas embolism.     

Introduction,establishment and spread of the Southern mouthbrooder Pseudocrenilabrus philander in the Baakens River,Eastern Cape,South Africa

This paper provides evidence for the extralimital establishment and spread of Pseudocrenilabrus philander in the Baakens River, Eastern Cape, South Africa. Since the first occurrence record at a single locality in 1994 this species has now spread throughout the river and the population contains both reproductive adults and juveniles. Gut content analysis demonstrated potential dietary overlap with native fishes and predation on fish larvae. Pseudocrenilabrus philander in the Baakens River therefore satisfies all criteria for an invasive species in this river and was categorised as invasive using a unified framework for biological invasions.     

Redescription of Hadogenes zumpti Newlands & Cantrell 1985: an unusual rock scorpion (Scorpiones,Ischnuridae) from the Richtersveld,South Africa

Hadogenes zumpti Newlands & Cantrell 1985 (Scorpiones, Ischnuridae), from the Richtersveld, South Africa, is redescribed. This is the only species of Hadogenes Kraepeiin 1894 in which the adults of both sexes are without a lobe at the base of the movable finger of the chela. The significance of the presence or absence of this lobe as a character within Hadogenes, particularly with respect to the taxonomically difficult Hadogenes tityws (E. Simon) species complex, is discussed.     

A New Freshwater Goby (Teleostei: Gobiidae) from the Pongolo Floodplain,Zululand, South Africa

A new freshwater goby, Mugilogobius pongolensis sp. n. is described and figured as a species new to southern and eastern Africa. This record extends the zoogeographcal distribution of Mugilogobius Smitt, 1899, from the Indonesian archipelago and South Australia to the Indian Ocean and the eastern coast of Africa.     

Dry matter yield and nutritional value of companion crops,intercropped with maize,for grazing purposes in northwestern KwaZulu-Natal

The northwestern part of KwaZulu-Natal (KZN) in South Africa is suitable for sheep farming as well as crop production. However, there are some constraints to animal production due to the low quality of natural vegetation during winter. Alternative winter feeding strategies have been suggested from research conducted in similar vegetation types in other parts of South Africa. Grazing maize is a potential alternative fodder source but its low crude protein might be a limitation to acceptable livestock production. This preliminary study investigated the potential of inter-cropping maize with high protein content crops for providing sheep with fodder of acceptable quality during winter in northwestern KZN.

Raphanus sativus (Japanese radish), Ornithopus sativus (serradella) and Vicia dasycarpa (grazing vetch) showed promising results in terms of dry matter yield and nutritional value. The production of Pennisetum glaucum (babala) and Avena sativa (oats) was relatively high. However, the nutritional value of both these species was marginal. Glycine max (soybeans) and Lablab purpureus (dolichos) showed good and above required nutritional properties, but dry matter yield was low.     

Introduction to an evaluation of the protection status of South Africa's vertebrates

During the Zoological Society of Southern Africa's 1994 Symposium in Pietermaritzburg, a theme session was convened to evaluate the protection status of selected groups of South African vertebrates (viz. freshwater fish, frogs, tortoises and terrapins, snakes, birds, and various mammal orders). The research papers presented during that session are reported in this number of the South African Journal of Zoology. The rationale behind the research, and the data and methods used, are described in this introductory paper. South Africa's national and international contractual obligations to conserve its biodiversity, and the urgent need for a national conservation strategy and national conservation information networks and databases, are also discussed.     

Otoliths versus scales: evaluating the most suitable structure for ageing largemouth bass,Micropterus salmoides,in South Africa

The suitability of scales for ageing Micropterus salmoides was determined by comparing the precision of growth zone counts on scales with those obtained from sectioned sagittal otoliths from a sample of 496 fish collected from Wriggleswade and Mankazana Impoundments in the Eastern Cape, South Africa. Otoliths (1.4% rejected) were more readable than scales (41.7% and 7.5% rejected) for Wriggleswade and Mankazana Impoundments respectively. Otolith readings were more precise (average percentage error (APE) = 13.6%; coefficient of variation (CV) = 15.8%) than scales (APE = 18.0%; CV = 21.9%) for the total sample. Growth zone counts between structures were not symmetrically distributed around the agreed ages (otolith age = scale age) of the fish from Wriggleswade Impoundment (Bowker’s test H²: χ² = 136, d.f. = 27, P < 0.05) and graphical comparison showed that scales tended to underestimate age, particularly for fish older than five years. Scales are therefore not suitable structures for ageing South African M. salmoides which may attain ages of up to 13 years.     

Are melanistic populations of the Karoo girdled lizard,Karusasaurus polyzonus,relics or ecotypes? A molecular investigation

It has been proposed that melanism in cordylids evolved in response to a single climatic event and that melanistic populations of Karusasaurus polyzonus are relictual. This study investigates the genetic relationships of melanistic and non-melanistic populations of K. polyzonus along the west coast of South Africa. Thirty-five specimens of K. polyzonus werecollected from three ‘melanistic’ and eight ‘non-melanistic’ sample localities. Partial sequence data were derived for two mitochondrial DNA loci (16S rRNA and nicotinamide adenine dinucleotide dehydrogenase component 2 (ND2)) and analysed using maximum parsimony, maximum likelihood and Bayesian inference. In addition, a haplotype network was constructed using TCS and an analysis of molecular variance (AMOVA) was conducted. The derived topologies were highly congruent and showed that melanistic and non-melanistic populations were interdigitated on all tree topologies and a number of haplotypes were shared between melanistic and non-melanistic specimens. These results suggest that melanistic populations of K. polyzonus are ecotypes, not relics.     

Diet of largemouth bass,Micropterus salmoides (Centrarchidae), an invasive alien in the lower reaches of an Eastern Cape river,South Africa

Largemouth bass (Micropterus salmoides) have been introduced to many South African river systems where they become invasive and pose a threat to native biota. The diets of small (32–138 mm TL) and large (192–448 mm TL) sized bass were analysed and compared in a marine fish nursery area in the lower Kowie River on the warm temperate coast of South Africa over a one-year period from March 2009 to February 2010. Dietary differences were detected between the two size groups. Amphipod sp. (% index of relative importance (IRI) = 69.2) and dipterans (Insecta) (%IRI = 21.9) dominated gut contents of small bass while larger bass preyed mostly on odonates (Insecta) (%IRI = 16.3) and the brachyuran Potamonautes sidneyi (%IRI = 80.0). Fish prey was of low importance during this study but comparisons with previous work on the lower Kowie River showed that when the river is flowing, young marine fish recruiting into the freshwater from the estuary become important prey items. These data suggest that in the lower Kowie River bass utilize invertebrate prey at low fish prey abundance and opportunistically feed on migrant fish when these are available.     

Notes on the New Zealand Kiwis (I)

Extract

Four species of Kiwi are recognized, one in the North Island and three in the South Island. The North Island species is referred to simply as the North Island Kiwi (Apteryx mantelli).The feathers are black about the shaft and fade into reddish brown. The “coat” of the bird is harsh to the touch. Its southern equivalent is known as the South Island Kiwi (Apteryx australis) and is slightly larger and rather greyer than the North Island bird. The feathers are soft. A little smaller than the North Island Kiwi is the Large Grey or Large Spotted Kiwi (Apteryx haasti),whilst the smallest of this group is the Little Grey or Little Spotted Kiwi (Apteryx oweni).     

The life-cycle and seasonal abundance of Echinoparyphium montgomeriana n. sp. (Trematoda: Echinostomatidae) in Natal,South Africa

A new species of Echinoparyphium, E. montgomeriana, is described from Durban, South Africa. Certain unusual aspects of its morphology are discussed. The adult fluke is a parasite of the alimentary tract of birds. Its larval stages are common parasites of freshwater snails belonging to the family Planor-bidae including Buiinus africanus,the intermediate host ofSchistosoma haematobium and S. mattheei in the area. These intra-molluscan stages are shown to have a seasonal transmission cycle.