The Anostraca are a group of crustaceans belonging to the class Branchiopoda. They are predominantly restricted to temporary, inland waterbodies, which in southern Africa, include rockpools, animal wallows, and large "pans". The anostracan fauna of southern Africa was last examined in detail in 1929 by Barnard, and recent collecting in a number of areas indicated the need to update earlier work. A total of four genera, each belonging to a separate family, and forty-six species, some of which had not previously been described, are presented in this thesis. The monogeneric family Streptocephalidae is well represented in Africa, and the fauna of Africa south and north of the Zambezi and Kunene Rivers, as well as Madagascar is reviewed. The Streptocephalus species are characterised by having an S-shaped antennal process, terminating in a cheliform "hand" region. The species were divided into ten groups based on similarities in antennal process morphology. The descriptions of five new species have been published, and an update on distribution and specimen data for a number of species are presented. An additional, as yet unpublished new species from Zimbabwe is presented. The genus Artemia, although well researched in other parts of the world, has been largely ignored in southern Africa. Bisexual populations occur along the Cape coast, and a set of specimens from Namibia, which includes only females, may indicate that A. parthenogenetica is also present on the subcontinent. The frontal knob morphology of the Cape specimens is similar to that of A. tunisiana from northern Africa and the Mediterranean. The family Branchipodidae is characterised by the fusion of the basal joints of the male antennae to form a so-called "clypeus". This family is represented in southern Africa by a diverse fauna of the genus Branchipodopsis. Eleven previously described species, as well as five new species are presented. An attempt was made to divide the sixteen species into species groups, as was done for the streptocephalids, but this proved difficult. The taxonomically useful characters in this genus are largely restricted to the basal processes. An additional character, the presence of expansions of the posterior thoracic segments in the females of some species could be useful. Much intraspecific variation in clypeus morphology was evident, particularly in two of the widespread species. Branchipodopsis species commonly occur in small pools which fill a number of times during the wet season and this has probably led to the development of localised adaptations, and intraspecific variation, or even species endemic to very restricted areas. Three sets of specimens which belong to the family Branchipodidae, but to no known genus, were recently collected from north-eastern Natal, the eastern Cape and the Namib desert in Namibia. These specimens share a single, large process positioned medianly on the fused basal joints, as opposed to a pair of processes in this position. However, the morphology of the penes, and the position and form of other antennal processes could indicate that the specimens are not congeneric. Unfortunately, more material is necessary before the descriptions of two of these possible new genera can be published. Three species of the genus Branchinella, of the family Thamnocephalidae, occur in southern Africa. These species have a well developed frontal process, and fully retractible penes. Bran chin ella spinosa was recorded from the Makgadikgadi Pan in northern Botswana, and was probably introduced to this area from north Africa, or Europe, where it has a wide distribution. The other two southern African species have been collected from few localities, and in small numbers, and this may be connected to cyst hatching processes. The southern African anostracan fauna exhibits distinct distribution patterns and these . appear to be influenced by climate, with rainfall having the dominant influence in the western half of the subcontinent, and temperature influencing distribution in the eastern half. The high altitude Escarpment forms a barrier to the movement of species between the coastal margin and the central plateau region. The formation of the Escarpment could have resulted in vicariance speciation in some anostracans, but in most cases, allopatric speciation appears to have occurred. The type of habitat also influences species distribution in a number of ways. The great anostracan species richness in southern Africa is probably related to the climatic heterogeneity of the subcontinent, as well as the possible origin of two genera in Gondwanaland, and the absence of a Pleistocene glaciation in Africa. Large parts of southern Africa have not been sampled, and the exact status and distribution of many species is uncertain. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1994.

Made available in DSpace on 2016-06-02T19:32:03Z (GMT). No. of bitstreams: 1 4487.pdf: 9817618 bytes, checksum: 69f8c99f3afd64a7838c3a29cded6830 (MD5) Previous issue date: 2012-06-06 / Universidade Federal de Sao Carlos / Ecological short-term studies were conducted in three temporary ponds where naturally occurs the fairy shrimp Dendrocephalus brasiliensis, focusing mainly on structure and dynamics of zooplankton. These ponds are located at Minas Gerais State, Brazil. Samples were collected just after the rainy season of 2011, during seven consecutive days in the two first ponds (P1 and P2) and six days in the third pond (P3). The three environments were shallow and showed high temperatures during the sampling period. Were also determined the concentrations of nutrients, suspended material and chlorophyll a in the water in the studied environments. The values of these variables increased after heavy rain. Qualitative and quantitative analyses of zooplankton community showed low richness in these ponds and diversity indices are specially related to rain. Number and relative abundance of zooplankton groups were related to the presence and density of D. brasiliensis. Analysis of phytoplankton and chlorophyll a showed that ponds with higher phytoplankton density seem to be favorable for some zooplankton groups such as rotifers and of D. brasiliensis. High densities of D. brasiliensis cysts in the sediments of the temporary ponds studied indicate that this species is well established in these environments. The CCA and Monte Carlo analyses demonstrate that most of the zooplankton community in the three temporary ponds were related with variable chlorophyll a. / Foram realizados estudos ecológicos de curta duração em três lagoas temporárias, onde ocorre naturalmente o anostráceo Dendrocephalus brasiliensis, com enfoque principal na estrutura e na dinâmica da comunidade zooplanctônica. Estas lagoas estão localizadas no Estado de Minas Gerais, Brasil. As amostras foram coletadas logo após a estação chuvosa em 2011, durante sete dias consecutivos nas duas primeiras lagoas (P1 e P2) e durante seis dias na terceira lagoa (P3). Os três ambientes eram rasos e tiveram altas temperaturas durante o período de amostragem. Também foram determinadas as concentrações de nutrientes, de material em suspensão e de clorofila a na água dos ambientes estudados. Os valores destas variáveis aumentou após chuva forte. Análises qualitativa e quantitativa da comunidade zooplanctônica indicaram baixa riqueza de espécies nessas lagoas e os índices de diversidade estiveram especialmente relacionados a ocorrência de chuva durante parte do período amostral. A abundância relativa e densidade numérica dos grupos zooplanctônicos estiveram relacionados com a presença e densidade de D. brasiliensis. Análises fitoplanctônicas e de clorofila a mostraram que lagoas com alta densidade fitoplanctônica podem ser favoráveis a alguns grupos como os rotíferos e altas densidades de D. brasiliensis. A alta densidade de cistos de D. brasiliensis, nas lagoas temporárias estudadas indica que esta espécie está bem estabelecida nestes ambientes. As análises de CCA e Monte Carlo demonstram, em maior parte que, a comunidade zooplanctônica nas três lagoas temporárias, estiveram relacionadas, com a variável clorofila a.