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2.
Zootaxa ; 4933(2): zootaxa.4933.2.5, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33756798

RESUMO

A new species of the cosmopolitan jellyfish genus Aurelia is described from the coastal waters of Mozambique using a combination of morphological, meristic and genetic information (COI and 18S). The species can be separated from congeners that have been recently described by a combination of bell shape, number of canal origins and anastomoses, and the shape of the manubrium and oral arms. Three types of nematocysts are present in the tissues of both the bell margin and oral arms, and this description of the cnidome will allow for future comparison. Pairwise genetic comparisons showed a mean COI divergence of 4.8% within the group, and a mean divergence ranging between 15% and 22% with all other species of Aurelia.


Assuntos
Cnidários , Cifozoários , Animais , Moçambique , Nematocisto
3.
PeerJ ; 9: e10697, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33520464

RESUMO

Although ctenophores can be conspicuous components of the plankton in coastal marine ecosystems, only six species have been formally described from around South Africa. Using photographs from local community scientists, we add a further three species (Cestum veneris, Beroe forskalii?, Ocyropsis maculata?) and six morphospecies to the regional fauna. These additions suggest that South Africa has a ctenophore fauna that is amongst the most diverse, globally; an observation in agreement with information from other taxa. Tips on how community scientists can improve their photographic contributions to understanding ctenophore diversity are provided.

4.
Zootaxa ; 4820(1): zootaxa.4820.1.5, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-33056083

RESUMO

Non-studied museum collections are hidden treasures-a source of information for various research fields. The novel taxa presented here were discovered during taxonomic examination of the backlogs of Bryozoa (Cheilostomata) from the Iziko South African Museum. We describe one new genus, Khulisa n. gen., and nine new species of bryozoans from South Africa. The new species are: Biflustra adenticulata n. sp., Aspidostoma sarcophagus n. sp., ?Micropora erecta n. sp., Trypostega richardi n. sp., Khulisa carolinae n. gen. et n. sp., Adeonella assegai n. sp., Hippomonavella lingulata n. sp., Phidolopora chakra n. sp. and Reteporella ilala n. sp. Three genera, Biflustra, Phidolopora and Triphyllozoon, are recorded for the first time from South Africa. This study highlights the importance of examining existing backlogged material lodged in museum collections.


Assuntos
Briozoários , Animais , Invertebrados , Museus
5.
Zootaxa ; 4896(3): zootaxa.4896.3.4, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33756859

RESUMO

Sixteen species of Latrunculiidae Topsent, 1922, belonging to the genera Latrunculia du Bocage, 1869, Strongylodesma Lévi, 1969, Cyclacanthia Samaai Kelly, 2004, Samaai Kelly, 2002, are currently known from the temperate waters of South Africa. Extensive new sponge collections from the Amathole region of South Africa revealed the existence of three new species of Tsitsikamma, T. amatholensis sp. nov., T. madiba sp. nov., and T. beukesi sp. nov., and a new species of the endemic South African genus Cyclacanthia, C. rethahofmeyri sp. nov. With the recent addition of two new species of Tsitsikamma from Algoa Bay and Tsitsikamma National Park (T. michaeli Parker-Nance, 2019; T. nguni Parker-Nance, 2019) the total number of known South African Latrunculiidae is now 20 species in four genera. Here we propose two new subgenera of Tsitsikamma, Tsitsikamma Samaai Kelly, 2002 and Clavicaulis subgen. nov., based on the morphological groups "favus" and "pedunculata" hypothesized by Parker-Nance et al. (2019). Species in the nominotypical subgenus Tsitsikamma, containing the type species, are thick encrusting to hemispherical with a rigid honeycombed choanosome, while species in the new subgenus Clavicaulis subgen. nov. have a purse or sac-like morphology with little choanosomal structure. Despite the obvious species-level differences in morphology, multivariate analysis based on spicule measurements (anisostyle length, discorhabd length, shaft and whorl length) was not able to distinguish between the proposed Tsitsikamma species, but separated known species T. favus Samaai Kelly, 2002, T. pedunculata Samaai Kelly, 2003, and T. scurra Samaai Kelly, 2003, from each other. Similarly, DNA barcoding of the mitochondrial COI  and the nuclear ITS of Tsitsikamma specimens failed to clearly differentiate between species, but was able to differentiate sister taxon relationships within the Latrunculiidae.


Assuntos
Poríferos , África Austral , Animais , DNA
6.
J Fish Biol ; 94(3): 498-511, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30702148

RESUMO

The basic biology and ecology of the South African east coast round herring Etrumeus wongratanai was investigated from samples of fish collected between 2013 and 2016. This species is short-lived and reaches a maximum of 3 years of age, with rapid growth in its first year of life. It reproduces from June to December (austral summer) and condition factor was lowest in May through to August and increased from September, probably reflecting the physiological strain before and during spawning. Fish larvae were the most important food items consumed during summer, whereas eucalanid copepods were the most important prey at other times of the year. Stable-isotope data suggest that there are gradual changes in the trophic level with increasing fish size, δ15 N and δ13 C values also differed between seasons. The results obtained here are compared with those of other Etrumeus species, regionally and globally.


Assuntos
Dieta/estatística & dados numéricos , Peixes/crescimento & desenvolvimento , Reprodução , Estações do Ano , Animais , Copépodes , Ecologia , Comportamento Alimentar , Feminino , Marcação por Isótopo , Masculino , Estado Nutricional , Alimentos Marinhos , Maturidade Sexual , África do Sul , Zooplâncton
7.
Zootaxa ; 4347(3): 592-594, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29245588

RESUMO

Tethya samaaii Ribeiro & Muricy, 2011 is a massive, irregularly globular or sub-spherical sponge with basal rooting processes or a disc-like attachment (Figure 1A). It was described from Oudekraal, on the west coast of South Africa as Tethya rubra Samaai & Gibbons, 2005 based on specimens collected during two surveys in 1996 (Samaai & Gibbons 2005). This species was later reported from Algoa Bay, on the southeast coast of South Africa by Waterworth et al. (2017).


Assuntos
Poríferos , Animais , Hylobates , África do Sul
8.
Zootaxa ; 4254(1): 49-81, 2017 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-28609981

RESUMO

S. dandelenae sp. nov. is described from the west coast of South Africa and occurs at depths of 80-500 m among unconsolidated sediments. Specimens can reach 40 cm in length and in some areas off South Africa, up to 18 tons/km2 can be collected in a single demersal trawl. Morphologically, the sponge is straw yellow, massive with rounded lobes and has a velvety surface: it is characterized by subradiate, irregular reticulation of bundles of tylostyles and tylostrongyles. Specimens of S. dandelenae sp. nov. have three size classes of tylostyles with the largest tylostyle lengths being 516 µm (441-614 µm), medium tylostyle lengths being 352 µm (307-422 µm) and the shortest tylostyle lengths being 215 µm (153-288 µm). Apart from the presence of tylostyles, some specimens of S. dandelenae sp. nov. also possess centrotylostongyles/oxeas, tylostrongyles and microacanthostrongyles spicules. We have used morphological characters to distinguish this species and a molecular marker (cox1) to conform that all specimens are the same species. At the spicular level, S. dandelenae sp. nov. is characterized by a complex of spicule types that vary with specimen size. Following a histological investigation and re-description of the holotypes of S. ficus (Johnston, 1842) and S. tylobtusus Lévi, 1958, and comparisons with S. carnosus (Johnston, 1842), S. stilensis Burton, 1933, and other Suberites species described from the African region, it is clear that the new species is different in spicule morphology, spicule size and external morphology. For example, microacanthostrongyles are not present in S. tylobtusus and S. carnosus, whilst S. ficus possesses a second, non-spinose category of microstrongyles. Suberites tylobtusus has tylostyles that are sometimes polytylote, with heads either well formed, pear shaped or reduced, in only one size catogory. The 'tylobtuse' condition of the tylostyles is also different to the kidney-shaped and centrotylostrongyles found in S. dandelenae sp. nov. Suberites stilensis Burton, 1933 has larger and thicker tylostyles (800 µm length x 10 µm thick) than those of S. dandelenae sp. nov. A comparative analysis of partial cox1 sequences from morphologically diverse specimens of S. dandelenae sp. nov. with published material indicates that all specimens comprise a monophyletic clade. The combined morphological and genetic data support the designation of Suberites dandelenae sp. nov.


Assuntos
Suberites , Animais , Ecossistema , Poríferos , África do Sul
9.
Fish Oceanogr ; 24(Suppl 1): 88-101, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26167105

RESUMO

Hypoxia [O2 < 2.0 mL L-1 (87 µmol kg-1)] and severely hypoxic water masses [O2 < 0.5 mL L-1 (21.8 µmol kg-1)] are increasing in coastal marine ecosystems due to eutrophication and warming. Here, we investigate the response of the suboxic-tolerant endemic fish, Sufflogobius bibarbatus, to variations in the thermal and oxygen environment, as well as to predation pressure, using 22 yr worth of satellite and in situ data. We show that environmental variation and predation pressure affect the goby population, which has expanded over the last decade while that of horse mackerel has contracted. These changes co-occurred with a general warming in the north and central shelf areas (north of 24.5°S). Spring warming positively affected both goby and hake abundances, but not the horse mackerel, suggesting different responses to surface temperature. The goby habitat contracted when predators were abundant, particularly in the north, which is the fringe of its distributional area. The implications of the differential tolerance of gobies and their predators for climate variations are discussed.

11.
Science ; 329(5989): 333-6, 2010 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-20647468

RESUMO

Since the collapse of the pelagic fisheries off southwest Africa in the late 1960s, jellyfish biomass has increased and the structure of the Benguelan fish community has shifted, making the bearded goby (Sufflogobius bibarbatus) the new predominant prey species. Despite increased predation pressure and a harsh environment, the gobies are thriving. Here we show that physiological adaptations and antipredator and foraging behaviors underpin the success of these fish. In particular, body-tissue isotope signatures reveal that gobies consume jellyfish and sulphidic diatomaceous mud, transferring "dead-end" resources back into the food chain.


Assuntos
Adaptação Fisiológica , Ecossistema , Cadeia Alimentar , Perciformes/fisiologia , Cifozoários , Anaerobiose , Animais , Bactérias , Comportamento Animal , Biomassa , Fenômenos Fisiológicos Cardiovasculares , Digestão , Comportamento Alimentar , Pesqueiros , Peixes/fisiologia , Sedimentos Geológicos/microbiologia , Sulfeto de Hidrogênio/análise , Namíbia , Oxigênio/análise , Consumo de Oxigênio , Dinâmica Populacional , Comportamento Predatório , Água do Mar/química
12.
Trends Ecol Evol ; 24(6): 312-22, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19324452

RESUMO

Human-induced stresses of overfishing, eutrophication, climate change, translocation and habitat modification appear to be promoting jellyfish (pelagic cnidarian and ctenophore) blooms to the detriment of other marine organisms. Mounting evidence suggests that the structure of pelagic ecosystems can change rapidly from one that is dominated by fish (that keep jellyfish in check through competition or predation) to a less desirable gelatinous state, with lasting ecological, economic and social consequences. Management actions needed to stop such changes require tactical coping strategies and longer-term preventative responses based on fundamental and targeted research on this understudied group.


Assuntos
Cnidários/fisiologia , Ecossistema , Animais , Pesqueiros , Dinâmica Populacional
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