Complete larval development of the hermit crabs Clibanarius aequabilis and Clibanarius erythropus (Decapoda : Anomura : Diogenidae), under laboratory conditions, with a revision of the larval features of genus Clibanarius

The complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second and third pereiopods, and 5-11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process.info:eu-repo/semantics/publishedVersio

Breeding season of the hermit crab petrochirus diogenes (anomura : diogenidae) in the north coast of São Paulo state, Brazil

Petrochirus diogenes, one of the largest hermit crabs in the western Atlantic, was studied in the north coast of the State of São Paulo, Brazil, to determine its breeding season through the analysis of gonad development at a macroscopic level. The analysis of 999 crabs collected from 1995 to 1999, based on four categories of gonad development, showed that males present gonads in the advanced stage during all seasons, and although females present developed ovaries all year as well, the peak incidence is in the summer. The peak of recruitment occurs in the winter

Morphology and growth of the larval stages of Geograpsus lividus (Crustacea, Brachyura), with the descriptions of new larval characters for the Grapsidae and an undescribed setation pattern in extended developments

16 páginas, 19 figuras, 3 tablas.Among the eight currently recognized genera and 40 species belonging to the brachyuran crab family Grapsidae (Thoracotremata), the complete larval development is only known for three species of Metopograpsus. In this study, we investigated the larval development of Geograpsus lividus originating from Jamaica and reared under controlled conditions in the laboratory. It consists of eight zoeal stages and the megalopa, representing the longest recorded developmental pathway for any brachyuran. Although long developments had been suggested for some species, based on specimens collected from the plankton, these were never confirmed by laboratory culture. In this study, zoeal growth (measured as increase in body size, dry mass, and contents of carbon, nitrogen, and hydrogen) is quantified, and morphological and meristic characters of the larval stages of G. lividus are described and illustrated. The development from hatching to the end of the zoeal phase took 2 months. During this time span, larval size (cephalothorax length) increased 4.4-fold, while the various measures of biomass increased by factors of 57–72. Morphologically, the larvae present most characters previously established for the family Grapsidae. However, the two last zoeal stages show new features that differ from the typical setation pattern known from grapsid species with only five zoeal stages. These were found in the number of natatory setae on the exopods of the maxillipeds and in the setation of the basis of the first maxilliped. Other characters, which had previously only been described for zoeae of Pachygrapsus and plankton-collected ones attributed to Planes, were observed also in G. lividus and could be confirmed as common features for the Grapsidae. Moreover, the larvae of G. lividus present a spinulation on the lateral and rostral spines of the cephalothorax. This character is recorded for the first time in grapsid crabs. A comparison of these observations is made with those based on terminal zoeal stages of species belonging to other brachyuran families, where similar characters have been documented.Christoph D. Schubart was funded by a research grant DFG 1460/3-2. Klaus Anger was supported by traveling funds from BAH/AWI. Guillermo Guerao participation was funded by a postdoctoral fellowship from Ministry of Science and Education (INIA).Peer reviewe

Infrared thermography applied to the evaluation of metabolic heat loss of chicks fed with different energy densities

Brazil must comply with international quality standards and animal welfare requirements in order to maintain its position as world's largest exporter of poultry meat. With the scenario of global climate change there is the forecast of occurrence of extreme events with characteristics of both excess cold and heat for several regions of the country. This study aimed to evaluate the effectiveness of using images of infrared thermography to evaluate the loss of sensible heat in young broilers fed different dietary energy levels. Twenty birds were reared in a house with appropriate brooding using infrared lamps. Birds were distributed in a completely randomized experimental into two treatments: T1 (control diet with 2950 kcal ME/kg-1), and T2 (high-energy diet with 3950 kcal ME/kg-1). Infrared thermographic images of the birds were recorded for four consecutive days. One bird was randomly chosen per treatment, and had special images taken and analyzed. Average surface temperature of the body area was calculated using the surface temperature recorded at 100 spots (50 at the front and 50 at the lateral side of the bird's body). Mean surface temperature of the flock was calculated recording 100 spots on the group of birds. Total radiant heat loss was calculated based on the average data of surface temperature. The results indicated that the young broilers fed the high-energy diet presented a metabolic energy loss equivalent to 0.64 kcal h-1, while the birds fed with the control diet lost 2.18 kcal h-1. This finding confirms that oil supplementation to the diet reduces bird heat loss. The infrared camera was able to record young broilers' surface temperature variation when birds were fed diets with different energy contents