Composition, abundance and seasonality of fish larvae in the mouth of Durban harbour, KwaZulu-Natal, South Africa

Ichthyoplankton samples were collected every six weeks at night on consecutive ebb and flood tides over an 18-month period (June 1991–December 1992) at surface, middle and bottom depths near the entrance of Durban Harbour to investigate the composition, abundance, seasonality and developmental stages of fish larvae in the harbour. In all, 8 797 fish larvae, representing 144 species and 64 families were collected. The Clupeidae and Gobiidae were the dominant families, representing 30 and 15% of the total catch respectively. The most abundant larvae were the blueline herring Herklotsichthys quadrimaculatus, which contributed 29.7% of the total catch. Larvae of estuarine-independent species dominated the total catch, both in terms of density (78%) and number of species (81%). In all, 28 species dependent on estuaries at some stage in their life cycle were recorded; of these 13 were species totally dependent on estuaries. Temperature and salinity accounted for 31% of the variation in larval densities of estuarine-dependent species. Turbidity was a significant variable for estuarineindependent species, larval densities of the abundant species being negatively correlated to turbidity. Larvaldensity peaked mainly in August 1992 (winter), with a mean larval density of 118 larvae.100m-3. Larvae of estuarine-associated species were mainly at the flexion and postflexion developmental stages, whereas most larvaeof estuarine-independent species were at preflexion and flexion stages. Larval densities of certain estuarineassociated species (e.g. Argyrosomus sp.) were significantly higher in bottom samples, mainly on flood tides butalso on ebb tides, suggesting that selective tidal stream transport is a recruitment mechanism used by these species. The impact of harbour development is shown by the dominant marine component of the larval fish assemblage in the harbour. However, despite the seminatural estuarine environment of Durban Harbour, the high species diversity of fish larvae in the system indicates that the harbour is in a relatively good ecological condition

Nanomedical Theranostics in Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. New diagnostic and therapeutic strategies are needed to mitigate this public health issue. Advances in nanotechnology have generated innovative strategies for diagnosis and therapy in a variety of diseases, foremost in cancer. Based on these studies, a novel concept referred to as nanomedical theranostics, or the combinatory application of nanoparticulate agents to allow diagnostic therapy, is being explored to enable image-guided, personalized, or targeted treatment. Preclinically, theranostics have been gradually applied to CVD with several interesting and encouraging findings. This article summarizes studies and challenges of nanotheranostic strategies in CVD. It also evaluates nanotheranostic strategies that may potentially be utilized to benefit patients

Undifferentiated Connective Tissue Disease-Associated Interstitial Lung Disease: Changes in Lung Function

Undifferentiated connective tissue disease (UCTD) is a distinct clinical entity that may be accompanied by interstitial lung disease (ILD). The natural history of UCTD-ILD is unknown. We hypothesized that patients with UCTD-ILD would be more likely to have improvement in lung function than those with idiopathic pulmonary fibrosis (IPF) during longitudinal follow-up. We identified subjects enrolled in the UCSF ILD cohort study with a diagnosis of IPF or UCTD. The primary outcome compared the presence or absence of a ≥5% increase in percent predicted forced vital capacity (FVC) in IPF and UCTD. Regression models were used to account for potential confounding variables. Ninety subjects were identified; 59 subjects (30 IPF, 29 UCTD) had longitudinal pulmonary function data for inclusion in the analysis. After accounting for baseline pulmonary function tests, treatment, and duration between studies, UCTD was associated with substantial improvement in FVC (odds ratio = 8.23, 95% confidence interval, 1.27–53.2; p = 0.03) during follow-up (median, 8 months) compared with IPF. Patients with UCTD-ILD are more likely to have improved pulmonary function during follow-up than those with IPF. These findings demonstrate the clinical importance of identifying UCTD in patients presenting with an “idiopathic” interstitial pneumonia

Bi-Directional Sexual Dimorphisms of the Song Control Nucleus HVC in a Songbird with Unison Song

Sexually dimorphic anatomy of brain areas is thought to be causally linked to sex differences in behaviour and cognitive functions. The sex with the regional size advantage (male or female) differs between brain areas and species. Among adult songbirds, males have larger brain areas such as the HVC (proper name) and RA (robust nucleus of the arcopallium) that control the production of learned songs. Forest weavers (Ploceus bicolor) mated pairs sing a unison duet in which male and female mates learn to produce identical songs. We show with histological techniques that the volume and neuron numbers of HVC and RA were ≥1.5 times larger in males than in females despite their identical songs. In contrast, using in-situ hybridizations, females have much higher (30–70%) expression levels of mRNA of a number of synapse-related proteins in HVC and/or RA than their male counterparts. Male-typical and female-typical sexual differentiation appears to act on different aspects of the phenotypes within the same brain areas, leading females and males to produce the same behaviour using different cellular mechanisms

Development of a Halotolerant Community in the St. Lucia Estuary (South Africa) during a Hypersaline Phase

Background: The St. Lucia Estuary, Africa’s largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline conditions in its northern lakes. Methodology/Principal Findings: This study documents the changes that occurred in the biotic communities at False Bay from May 2010 to June 2011, in order to better understand ecosystem functioning in hypersaline habitats. Few zooplankton taxa were able to withstand the harsh environmental conditions during 2010. These were the flatworm Macrostomum sp., the harpacticoid copepod Cletocamptus confluens, the cyclopoid copepod Apocyclops cf. dengizicus and the ciliate Fabrea cf. salina. In addition to their exceptional salinity tolerance, they were involved in a remarkably simple food web. In June 2009, a bloom of an orange-pigmented cyanobacterium (Cyanothece sp.) was recorded in False Bay and persisted uninterruptedly for 18 months. Stable isotope analysis suggests that this cyanobacterium was the main prey item of F. cf. salina. This ciliate was then consumed by A. cf. dengizicus, which in turn was presumably consumed by flamingos as they flocked in the area when the copepods attained swarming densities. On the shore, cyanobacteria mats contributed to a population explosion of the staphylinid beetle Bledius pilicollis. Although zooplankton disappeared once salinities exceeded 130, many taxa are capable of producing spores or resting cysts to bridge harsh periods. The hypersaline community was disrupted by heavy summer rains in 2011, which alleviated drought conditions and resulted in a sharp increase in zooplankton stock an

Review of the projected impacts of climate change on coastal fishes in southern Africa

The coastal zone represents one of the most economically and ecologically important ecosystems on the planet, none more so than in southern Africa. This manuscript examines the potential impacts of climate change on the coastal fishes in southern Africa and provides some of the first information for the Southern Hemisphere, outside of Australasia. It begins by describing the coastal zone in terms of its physical characteristics, climate, fish biodiversity and fisheries. The region is divided into seven biogeographical zones based on previous descriptions and interpretations by the authors. A global review of the impacts of climate change on coastal zones is then applied to make qualitative predictions on the likely impacts of climate change on migratory, resident, estuarine-dependent and catadromous fishes in each of these biogeographical zones. In many respects the southern African region represents a microcosm of climate change variability and of coastal habitats. Based on the broad range of climate change impacts and life history styles of coastal fishes, the predicted impacts on fishes will be diverse. If anything, this review reveals our lack of fundamental knowledge in this field, in particular in southern Africa. Several research priorities, including the need for process-based fundamental research programs are highlighted

A preliminary assessment of impacts on estuarine associated fauna resulting from an intra-basin transfer and fresh water ion from aquatic systems in the Richards Bay area of KwaZulu-Natal, South Africa

An intra-basin transfer and the ion of water from aquatic systems in the Richards Bay area has led to the construction of six barriers which are restricting faunal movement, a reduction of flow to the Mhlathuze and Nhlabane estuaries and changes in the physico-chemical characteristics of four coastal lakes. These factors have severely impacted on the fauna of the aquatic systems in the area, particularly the fish but also the macrocrustacea and benthos. Preliminary results show that the structure of the interlinked marine-estuarine-river-coastal lakes ecosystem has been disrupted due to a cessation of migratory movements by the fauna which cannot cross the barriers. It is concluded that the construction of fishways will substantially contribute to reducing the current impacts and that the possibility exists that most will be in place within the next two to three years. Keywords: coastal lakes; KwaZulu-Natal; South Africa; estuarine fauna; fish; barriers; interbasin transfers; freshwater ion (Afr J Aqua Sci: 2001 (26): 115-120

The state of knowledge of water quality and major biotic components of the Richards Bay coastal lakes DP Cyrus

This note briefly introduces the concept of the Environmental Reserve of the new Water Act as well as the set of papers that follow that deal with specific components of the four coastal lakes at the lower end of the Mhlathuze System. These were originally prepared for the Department of Water Affairs and Forestry Lake Water Requirements study of the system. Each paper forms an up-to-date review of its specific topic. Keywords: environmental reserve; biotic components; water quality; review (Afr J Aqua Sci: 2001 26(2): 75-76

Aquatic avifauna of the coastal lakes of the Mhlathuze River system

This paper provides the first attempt to bring together all published and unpublished data on the aquatic avifauna of Lakes Mzingazi, Nsezi, Cubhu and Mangeza, situated near Richards Bay in the lower reaches of the Mhlathuze River system. Whilst the amount of data located was limited, it does show that the systems support a varied and important avifauna, including a number of Red Data species. The lack of survey data for these systems is highlighted, indicating the need for a survey of available water bird habitats to be undertaken at each of the lakes. In addition, the changes that might occur in the avifauna if the lakes were exposed to water level draw-downs or rises is assessed. Keywords: aquatic avifauna; review; conservation priorities; information gaps; coastal lakes; Richards Bay; South Africa (Afr J Aqua Sci: 2001 26(2): 77-83