Nutritional potassium requirement for laying Japanese quails

The objective of this study was to evaluate the potassium requirement for laying Japanese quails. Two hundred and forty quails were distributed in a randomized block design, with five treatments and six replicates, with eight birds each. The treatments consisted of a basal diet deficient in potassium (K) (2.50 g/kg), supplemented with potassium carbonate, to replace the inert, to reach levels of 2.50, 3.50, 4.50, 5.50 and 6.50 (g/kg) of K in the diet. There was a quadratic effect of K levels on feed intake, egg production, egg mass and feed conversion per egg mass and per egg dozen, estimating the requirements of 4.26, 4.41, 4.38, 4.43 and 4.48 (g/kg) of K diet, respectively. There was no significant effect on the levels of K in the diet on egg weight, albumen weight, percentage of yolk or shell and yolk color. However, yolk and shell weights reduced and the albumen percentage increased linearly with increasing levels of K in the diet. Despite the reduction of shell weight, the increased levels of K did not influence the specific gravity and shell thickness. The use of 4.41 g/kg of potassium is recommended in the diet for laying Japanese quails

Dynamics of gonadal development of Aegla platensis Schmitt (Decapoda, Anomura, Aeglidae)

One way to estimate gonadal development through the reproductive cycle is to observe the growth of the gonads related to the organs used to store energy. The aim of this study was to follow the gonadosomatic and hepatosomatic indexes during annual cycle of Aegla platensis Schmitt, 1942. Adult animals were collected in Taquara, Rio Grande do Sul, Brazil (29&deg;46'S, 50&deg;53'W). Males and females were initially weighed and dissected and had their gonads and hepatopancreas (HP) removed and weighed in order to estimate the Gonadosomatic (GI) and hepatosomatic (HI) indexes. In females, the indexes were also compared to the degree of development of the ovaries. In males the GI showed a peak of gonadal development in the autumn (p < 0.05), just when the HI showed a decrease (p < 0.05). Females showed a rise in the GI at the end of summer and beginning of autumn (p < 0.05). In females, GI values increased as the ovary matured. In A. platensis, for both males and females, the HI never showed values lower than the GI, which may indicate that these aeglids show a different pattern of energy utilization from other decapods, where as gonadal development peaks the HI decreases markedly.<br>Uma maneira de estimar o desenvolvimento gonadal ao longo do ciclo reprodutivo é observar o crescimento das gônadas em relação aos órgãos utilizados para o estoque de energia. O objetivo desse estudo foi acompanhar os índices gonadossomático e hepatossomático durante o ciclo reprodutivo de Aegla platensis Schmitt, 1942. Animais adultos foram coletados em Taquara, Rio Grande do Sul, Brasil (29&deg;46'S, 50&deg;53'W). Machos e fêmeas foram pesados e dissecados, gônadas e hepatopâncreas (HP) foram retirados e pesados para obtenção dos índices gonadossomático (IG) e hepatossomático (IH). Nas fêmeas, os índices também foram comparados com o grau de desenvolvimento dos ovários. Nos machos o IG mostrou um pico de desenvolvimento gonadal no outono (p < 0,05), quando os valores do IH diminuíram (p < 0,05). Fêmeas mostraram um aumento do IG no final do verão e início do outono (p < 0,05) e os valores do IG aumentaram à medida que o ovário tornava-se maduro. Em A. platensis, tanto nos machos como nas fêmeas, os valores do IH nunca mostraram valores mais baixos que o IG, o que pode indicar que esses aeglídeos apresentam um padrão de utilização de energia diferente dos outros decápodos, onde à medida que o desenvolvimento gonadal aumenta os valores do IH diminuem marcadamente

Diversity and distribution Patterns of the infralittoral green macroalgae from Potiguar basin, Rio Grande do Norte, Northeastern Brazil

Diversity and distribution pattern of the infralittoral green macroalgae at Potiguar basin, Rio Grande do Norte, Northeastern Brazil were analyzed from material collected at depths varying from 2 to 100 m. Collections were carried out with two types of dredges during four campaigns: July 2002, May and November 2003 and May 2004 at 43 stations. Chlorophyta is represented by 54 species, five varieties and three forms. The most representative family is Caulerpaceae, and the most diverse genus is Caulerpa, with 11 species. The results showed that most taxa (89%) are rare, and 10% are present at low frequencies. The most frequent species was Caulerpaprolifera (Forssk.) J.V. Lamour. occurring at almost all coastal and inner shelf stations, recorded in all campaigns. Species distribution by depth range showed that higher species number occurred on the inner shelf from 10 to 20 m, and a wide vertical distribution pattern was registered for Anadyomenestellata (Wulfen in Jacq.) C. Agardh,Chamaedoris peniculum (J. Ellis &amp; Solander) Kuntze, Codium isthmocladum Vickers, Microdictyon sp., Udoteaoccidentalis A. Gepp &amp; E. Gepp and Ventricaria ventricosa (J. Agardh) J.L. Olsen &amp; J.A. West. Four species, Cladophoracoelothrix Kütz., C.ordinata (Børgensen) C. Hoek, Caulerpellaambigua (Okamura) Prud'homme &amp; Lokhorst and Halimedasimulans M. Howe, were recorded for the first time in Rio Grande do Norte