The origin of Rattus rattus on the Îles Éparses,Western Indian Ocean

Tollenaere et al. (Journal of Biogeography, 2010, 37 , 398–410) present a phylogeographic analysis of Rattus rattus for the Western Indian Ocean, with particular emphasis on Madagascar, but do not include samples from three island groups centrally located in the Mozambique Channel. Haplotypes from these islands provide additional information on the colonization pathways of R. rattus in the Western Indian Ocean region. For each of the three Îles Éparses groups in the Mozambique Channel, we test the competing hypotheses that colonization by R. rattus was most likely: (1) from the Arabian Peninsula, (2) from East Africa, (3) from Madagascar, or (4) from independent shipping. These results are combined with historical observations of the presence of R. rattus on these islands to give stronger inference on the colonization pathways. Additionally, more accurate colonization dates provide guidance for contemporary conservation management.     

Did lemurs have sweepstake tickets? An exploration of Simpson's model for the colonization of Madagascar by mammals

Aim  To investigate the validity of Simpson's model of sweepstakes dispersal, particularly as it applies to the colonization of Madagascar by African mammals. We chose lemurs as a classic case.
Location  The East African coast, the Mozambique Channel and Madagascar.
Methods  First, we investigated the assumptions underlying Simpson's statistical model as it relates to dispersal events. Second, we modelled the fate of a natural raft carrying one or several migrating mammals under a range of environmental conditions: in the absence of winds or currents, in the presence of winds and currents, and with and without a sail. Finally, we investigated the possibility of an animal being transported across the Mozambique Channel by an extreme climatic event like a tornado or a cyclone .
Results  Our investigations show that Simpson's assumptions are consistently violated when applied to scenarios of over-water dispersal by mammals. We suggest that a simple binomial probability model is an inappropriate basis for extrapolating the likelihood of dispersal events. One possible alternative is to use a geometric probability model. Our estimates of current and wind trajectories show that the most likely fate for a raft emerging from an estuary on the east coast of Africa is to follow the Mozambique current and become beached back on the African coast. Given prevailing winds and currents, transport from Madagascar to Africa is very much more likely than the reverse process. Freak transport by means of a hurricane or tornado is even less likely than rafting for mammals.
Main conclusions  Our models suggest that the scenario of sweepstakes dispersal that currently enjoys wide support is not valid at either the theoretical or the applied level when applied to the hypothetical invasion of Madagascar by African mammals. Alternative explanations should be sought.     

Effects of food price shocks on child malnutrition: The Mozambican experience 2008/2009

A propitiously timed household survey carried out in Mozambique over the period 2008/2009 permits us to study the relationship between shifts in food prices and child nutrition status in a low income setting. We focus on weight-for-height and weight-for-age in different survey quarters characterized by very different food price inflation rates. Using propensity score matching techniques, we find that these nutrition measures, which are sensitive in the short run, improve significantly in the fourth quarter of the survey, when the inflation rate for basic food products is low, compared to the first semester or three quarters, when food price inflation was generally high. The prevalence of underweight, in particular, falls by about 40 percent. We conclude that the best available evidence points to food penury, driven by the food and fuel price crisis combined with a short agricultural production year, as substantially increasing malnutrition amongst under-five children in Mozambique.     

Four new species of Asparagus (Asparagaceae) from the Flora Zambesiaca area

Summary  Four new species of Asparagus (Asparagaceae) from the Flora Zambesiaca area are described and illustrated; the need for more collections is highlighted to assess their conservation status. Asparagus botswanicus Sebsebe is known from a single locality in Botswana; A. chimanimanensis Sebsebe occurs in Zimbabwe and Mozambique; A. richardsiae Sebsebe is known in Zambia and A. radiatus Sebsebe is from a small restricted area (Goba) in Mozambique and Umbeluzi Gorge in Swaziland.     

Modelling mangrove propagule dispersal trajectories using high‐resolution estimates of ocean surface winds and currents

Mangrove forests are systems that provide ecosystem services and rely on floating propagules of which the dispersal trajectories are determined by ocean currents and winds. Quantitating connectivity of mangrove patches is an important conservation concern. Current estimates of connectivity, however, fail to integrate the link between ocean currents at different spatial scales and dispersal trajectories. Here, we use high‐resolution estimates of ocean currents and surface winds from meteorological and oceanographic analyses, in conjunction with experimental data on propagule traits (e.g., density, size, and shape) and dispersal vector properties (e.g., strength and direction of water and wind currents). We incorporate these data in a dispersal model to illustrate the potential effect of wind on dispersal trajectories of hydrochorous propagules from different mangrove species. We focus on the Western Indian Ocean, including the Mozambique Channel, which has received much attention because of its reported oceanic complexity, to illustrate the effect of oceanic features such as eddy currents and tides. In spite of the complex pattern of ocean surface currents and winds, some propagules are able to cross the Mozambique Channel. Eddy currents and tides may delay arrival at a suitable site. Experimentally demonstrated differences in wind sensitivity among propagule types were shown to affect the probability of departure and the shape of dispersal trajectories. The model could be used to reconstruct current fluxes of mangrove propagules that may help explain past and current distributions of mangrove forests and assess the potential for natural expansion of these forests.     

Environmental Vibrio spp., isolated in Mozambique, contain a polymorphic group of integrative conjugative elements and class 1 integrons

Circulation of mobile genetic elements linked to drug resistance spread was studied in Vibrio strains isolated from surface urban water (river and sea) and shellfish samples in 2002-2003 in Maputo, Mozambique. Class 1 integrons and integrating conjugative elements (ICE) were investigated by PCR and mating experiments in strains of major health interest: 10 Vibrio cholerae, six Vibrio parahaemolyticus, two Vibrio alginolyticus and one Vibrio fluvialis. Resistance to at least two antibiotics (predominantly beta-lactams) was detected in all the strains, with additional resistances to sulfamethoxazole, spectinomycin, streptomycin and/or trimethoprim. Class 1 integrons contributed partially to the expression of drug resistance and were found in five isolates: four V. cholerae (blaP1 cassette, one strain also contained the dfrA15 cassette) and one V. alginolyticus (aadA2 cassette). ICEs, apparently devoid of resistance genes, were found in eight V. cholerae, three V. parahaemolyticus and one V. fluvialis isolates. A wide variability was observed by molecular characterization of ICEs. Five ICEs were included in the SXT/R391 family and seven ICEs were not classified. Our results indicate that the SXT/R391 family and related ICEs comprise a large class of polymorphic genetic elements widely circulating in environmental Vibrio strains in Africa, beside those evidently linked to drug resistance in clinical isolates.     

Idiomysis mozambicus, a new mysid species (crustacea: mysidacea) from Mozambique

Idiomysis mozambicus is described from coastal waters of Mozambique. The species can be distinguished from the other species of the genus by the one-segmented antennal scale, the two-segmented exopod of the fourth male pleopod and the bluntly pointed rostrum.     

Effects of seed traits on the potential for seed dispersal by fish with contrasting modes of feeding

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The immune response of tilapia Oreochromis mossambicus and its susceptibility to Streptococcus iniae under stress in low and high temperatures

Mozambique tilapia Oreochromis mossambicus acclimated to 27 degrees C were then held at 19, 23, 27 (control), 31 and 35 degrees C, and were examined for non-specific cellular and humoral responses after 12-96 h. Total leucocyte count decreased significantly when fish were transferred to 19 and 23 degrees C after 48 and 96 h, and when transferred to 35 degrees C over 12-96 h, respectively. Respiratory burst decreased significantly when fish were transferred to 19, 31 and 35 degrees C over 24-96 h, whereas phagocytic activity and phagocytic index decreased significantly when fish were transferred to low temperatures (19 and 23 degrees C) and high temperatures (31 and 35 degrees C) over 12-96 h. Lysozyme activity decreased significantly when fish were transferred to 19 degrees C after 12-96 h, but increased significantly when transferred to 31 and 35 degrees C over 48-96 h. Alternative complement pathway (ACH(50)) also decreased significantly when transferred to 19 and 23 degrees C after 12h, but increased significantly when transferred to 31 and 35 degrees C after 24h. In another experiment, tilapia reared at 27 degrees C were injected intraperitoneally with Streptococcus iniae at a dose of 1 x 10(7)colony-forming units (cfu)fish(-1), and then reared onward at water temperatures of 19, 23, 27 (control), 31 and 35 degrees C. Over 48-168 h, the cumulative mortality of S. iniae-injected fish held in 19 and 35 degrees C was significantly higher than that of injected-fish held in 23, 27 and 31 degrees C. It is concluded that transfer of tilapia O. mossambicus from 27 degrees C to low temperatures (19 and 23 degrees C) after 12h, and transfer of fish from 27 degrees C to high temperatures (31 and 35 degrees C) reduced their immune capability. Moreover, tilapia under temperature stress at 19 and 35 degrees C from 27 degrees C decreased its resistance against S. iniae.     

A revision of the hard coral genus Acropora Oken, 1815 (Scleractinia: Astrocoeniina: Acroporidae) in south-east Africa

All species of the scleractinian coral genus Acropora presently known to occur in south-east Africa (denoting the African coast south of the Tropic of Capricorn, and including the atoll Bassas da India in the Mozambique channel) are reviewed. Twenty-three species are discussed, most of which are of wide Indo-Pacific distribution. Field and laboratory characteristics of all species are described in detail. Species richness in southern Mozambique is much higher (23 species) than in South Africa (14 species), probably due to the higher ecological differentiation of Mozambiquan reefs. The Acropora fauna of the atoll Bassas da India is similar to that of Mozambique but with two additional species A. paniculata and A. cf. striata. Compared to other coral reef areas in similar latitudes, the south-east African Acropora fauna is of average diversity. An identification key to all species is provided.