Larval development of Gilchristella aestuaria (Gilchrist, 1914) (Pisces: Clupeidae) from southern Africa

The larval development ol the southern African endemic clupeid Gilchristella aestuaria is described and illustrated from specimens collected in the Swartvlei and Sundays estuarine systems of the Cape Province. Free embryos have no visible gut, unpigmented eyes and bodies, and are dependent on the yolk sac contents for nutrition. This stage lasts until about 4 mm body length (BL) when the eyes become pigmented and a gut becomes visible. Between 4 mm and 7 mm BL melanophores on the ventral aspect of the body form, and the dorsal and caudal lin anlagen develop. Between 7 mm and 8 mm BL the swimbladder lorms, flexion occurs and the anal fin anlage develops. By the 10 mm BL stage most of the skeletal elements have begun to differentiate, with the vertebral centra already showing signs of ossification. General ossification commences between 12 mm and 13 mm BL. All unpaired fins have the adult complement of rays by 15 mm BL. Scalation starts between 16 mm and 17 mm BL and is complete by 20 mm BL. Body depth increases gradually, from about 5% of BL in the early larval stages to >14% of BL in the juveniles. The pre-anal length decreases from about 87% of BL in the larvae to approximately 69% of BL in the juveniles. Head length increases from approximately 11% of BL in the larvae to 24-29% of BL in the juveniles. The larval snoui is initially 2% of BL, increasing to 7% of BL in the juvenile stages owing to the development of jaw elements

Increasing lifetime of recurrent sunspot groups within the Greenwich photoheliographic results

Long-lived (> 20 days) sunspot groups extracted from the Greenwich Photoheliographic Results (GPR) are examined for evidence of decadal change. The problem of identifying sunspot groups that are observed on consecutive solar rotations (recurrent sunspot groups) is tackled by first constructing manually an example dataset of recurrent sunspot groups and then using machine learning to generalise this subset to the whole GPR. The resulting dataset of recurrent sunspot groups is verified against previous work by A. Maunder and other Royal Greenwich Observatory (RGO) compilers. Recurrent groups are found to exhibit a slightly larger value for the Gnevyshev -aEuro parts per thousand Waldmeier Relationship than the value found by Petrovay and van Driel-Gesztelyi (Solar Phys. 51, 25, 1977), who used recurrence data from the Debrecen Photoheliographic Results. Evidence for sunspot-group lifetime change over the previous century is observed within recurrent groups. A lifetime increase of a factor of 1.4 between 1915 and 1940 is found, which closely agrees with results from Blanter et al. (Solar Phys. 237, 329, 2006). Furthermore, this increase is found to exist over a longer period (1915 to 1950) than previously thought and provisional evidence is found for a decline between 1950 and 1965. Possible applications of machine-learning procedures to the analysis of historical sunspot observations, the determination of the magnetic topology of the solar corona and the incidence of severe space-weather events are outlined briefly

Composição bromatológica e produção de efluente de silagens de capim-tanzânia sob efeitos do emurchecimento, do tamanho de partícula e do uso de aditivos biológicos Chemical composition and effluent yield of Tanzaniagrass silages affected by wilting, particle size and enzymatic/microbial additive

O presente trabalho foi conduzido para se avaliar o efeito do emurchecimento, da redução do tamanho das partículas e da adição de enzimas fibrolíticas (com ou sem inoculante bacteriano Lactobacillus plantarum) sobre a composição bromatológica da silagem e a produção de efluente em silagens de capim-tanzânia (Panicum maximum Jacq. cv. Tanzânia). A forragem foi cortada aos 45 dias de crescimento vegetativo e armazenada em silos experimentais (50 L) durante 136 dias. O efluente foi coletado e quantificado no 1º, 2º, 7º, 14º, 21º, 60º, 90º e 136º dias de armazenamento. A adição de enzimas fibrolíticas, associadas ou não ao inoculante bacteriano, promoveu redução da fração fibrosa (FDN, FDA, celulose e hemicelulose), que foi mais acentuada nas silagens emurchecidas. Contudo, não houve aumento da digestibilidade in vitro da MS com a adição de enzimas fibrolíticas. Embora tenha havido diferenças no tamanho de partícula, a amplitude alcançada não foi suficiente para provocar alterações significativas na composição química e no efluente das silagens. Observou-se que a quantidade total de efluente produzida foi maior (250L/t forragem ensilada) em silagens não-emurchecidas e esporádica nas emurchecidas. A adição de enzimas com ou sem inoculante bacteriano não aumentou as perdas por efluente. Os valores médios de DBO (11.289 mg/L), DQO (36.279 mg/L), DQO/DBO (3, 35), pH (4, 9) e de sólidos totais (34.395 mg/L) e sólidos totais fixos (16.533 mg/L) foram observados no efluente das silagens não-emurchecidas. As silagens não-emurchecidas apresentaram efluente com elevado potencial poluidor para o meio ambiente.<br>The present trial aimed to evaluate the effects of wilting (wet vs. wilted), particle size reduction (small vs. large) and the addition of fibrolytic enzymes (alone vs. combined with Lactobacillus plantarum) on the chemical composition and effluent yield of Tanzaniagrass silages (Panicum maximum Jacq. cv. Tanzania). The forage was harvested and cut at 45-day vegetative re-growth period and stored in the experimental plastic silos (50 L) during 136 days. During the storage period, the effluent flow was collected and measured at days 1, 2, 7, 14, 21, 60, 90 and 136. The addition of fibrolytic enzymes exclusively or combined with Lactobacillus plantarum led to decreased contents of NDF, ADF, cellulose and hemicellulose, mainly on wilted silages; however, no benefit was observed in the in vitro DM digestibility. Even though particles sizes were different, the range observed was not wide enough to show significant differences either on chemical composition or effluent yield in silages. The effluent yield was higher (250L/t ensiled forage) for the wet silages and sporadical for the wilted silages. The addition of fibrolytic enzymes exclusively or combined with Lactobacillus plantarum did not increase the effluent losses. Mean values for BOD (11, 289 mg/L), COD (36, 279 mg/L) and COD/BOD ratio (3.35) were observed on the effluent of wet silages. Wet silages resulted in higher of pollution to the environment