Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats

Peer reviewedPublisher PD

Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals

The use of lactic acid bacteria isolated from intestinal tract of Nile tilapia (Oreochromis niloticus), as growth promoters in fish fed low protein diets

In this study, the effect as growth promoter of five lactic acid strains (Enterococcus faecium, E. durans, Leuconostoc sp., Streptococcus sp. I and Streptococcus sp. II), isolated from intestinal tract of Nile tilapia (Oreochromis niloticus), was evaluated. Eight isocaloric diets were formulated: one containing 40% of protein as positive control, and seven with 27% protein. Five diets with 27% protein were supplemented with one of the isolated lactic acid bacteria in a concentration of 2.5x10(6) cfu g-1 of diet. A commercial probiotic based on S. faecium and Lactobacillus acidophilus was added at the same concentration to one 27% protein diet as a comparative diet, and the last diet was not supplemented with bacteria (negative control). Tilapia fry (280 mg basal weight) stocked in 15 L aquaria at a density of two per liter were fed for 12 weeks with experimental diets. Results showed that fry fed with native bacteria supplemented diets presented significantly higher growth and feeding performance than those fed with control diet. Treatment with Streptococcus sp. I isolated from the intestine of Tilapia produced the best growth and feeding efficiency, suggesting that this bacteria is an appropriate native growth promoter

Effect of the protein-lipids ratio on growth and maturation of the crayfish Procambarus (Austrocambarus) llamasi

The effect of six isocaloric diets with different protein (10%, 20% and 30%) and lipids (6% and 12%) contents was evaluated on growth and maturation of male and female juvenile P. llamasi crayfish. The experiment was carried out using individual plastic chambers within a closed, recirculating system with constant temperature. After 90 days, specific growth rate (SGR) values were generally low for both sexes. Lowest SGR for females was 0.4 with diet D1 (10/6) and highest was 0.7 with diet D4 (20/12). The lowest SGR for males was 0.3 with diet D1 (10/6) and the highest was 0.6 with diet D4 (20/12). Feed conversion ratio (FCR) varied from 1.1 to 1.8, and survival was generally high (> 80%) for both sexes. The Maturation Index (MI) behaved in a similar way to the Gonadosomatic Index (GI), manifesting a close relationship with dietary protein and lipids contents. Diet had a significant effect on maturation in females. The effect of protein and lipids content was significant with a direct relationship between these values and the MI and GI. Diets with the highest protein content had the best GI and MI values and all diets with 12% lipids had better MI and GI values than diets with 6%. Unlike the growth performance, the best maturation results were produced by the 30/12 diet. Based on the different observed effects of the diets on growth and maturation, it is recommended the use of a 20/12 diet for growth and a 30/12 diet for maturation. (c) 2005 Elsevier B.V. All rights reserved

The influence of the absence of light on the onset of first maturity and egg laying in the crayfish Procambarus (Austrocambarus) llamasi (Villalobos, 1955)

Procambarus llamasi is a crayfish species endemic to southeastern Mexico. Of all the portions of a species lifecycle to be understood, reproduction is the most vital. In order to better understand the effect of external factors on the reproductive development of P. llamasi, an experiment was done testing the influence of complete darkness (CD) and a natural light cycle (NL) on first maturity and egg laying. During the 90-day experiment, three tanks were covered with dark plastic to prevent light from entering (complete darkness, CD), and another three were covered with transparent plastic to allow a natural light cycle (14L:12D, NL). Sexually immature juveniles were placed in the tanks and their growth and sexual maturation monitored. At the end of the experiment, the general spawning mean was 24% for the CD treatment and 15% for the NL treatment. The maturation index was 4.04 for the CD and 3.88 for the NL, and the gonadosomatic index was 3.90 for the CD and 4.20 for the NL. In contrast to many other crayfish species, it is determined that complete darkness does not affect growth, survival or reproduction in P. llamasi. Reproductive development in this species may respond to other external factors such as hydrological cycles. (C) 2002 Elsevier Science B.V All rights reserved

Distribución geográfica actual de Procambarus (Austrocambarus) llamasi (Cambaridae) en la Península de Yucatán

There are two species of astacids of the genus Procambarus reported for the Yucatan Peninsula: Procambarus pilosimanus (Villalobos, 1955) and Procambarus llamasi (Villalobos, 1955). P. pilosimanus was only found in Quintana Roo, while P. llamasi is present from south Veracrzu to Campeche. This research was carried out with 129 collecting sites to determine P. llamasi distribution in the three states of the Yucatan Peninsula. In the present study P. llamasi was also found in Quinatana Roo, but P. pilosimanus was not collected in any of the sampling sites. At the northern region of Yucatan and Quintana Roo small number of organism were collected as it is  karstic area. High number of organism were easily found in the south part of Yucatan Peninsula where less permeable soils exist. The distribution of P. llamasi depend on the rainy season (July - October). It was difficult to collect them during the dry season (January - June) as part of its burying adaptation made it hard to found.Se conocen dos especies de astácidos del género Procambarus en la península de Yucatán: Procambarus polisimanus (Villalobos, 1995) y Procambarus llamasi (Villalobos, 1995). La primera fue registrada para el Estado de Quintana Roo, mientras que P. llamasi presenta una distribución del sur de Veracruz hasta el sur de Campeche. A partir del estudio de 129 sitios de colecta se determinó la presencia de Procambarus llamasi en los tres Estados de la Península de Yucatán. Se recolecto en Quintana Roo, donde no se había registrado anteriormente y sólo había registros de P. pilosimanus. En el norte de Yucatán y Quintana Roo, una zona cárstica, se recolectó un bajo número de ejemplares de P. llamasi, mientras que en el sur se facilitó su recolecta dado la menor permeabilidad de los suelos. La distribución de P. llamasi depende de los arrastres ocasionados durante la época de lluvias (julio a octubre). Difícilmente se le puede encontrar durante la época de secas (enero a junio) debido a su adaptación de enterramiento y deslizamiento entre las piedras

Nutritive value of four by-product meals as potential protein sources in diets for Octopus maya

The nutritional value of four meals made from animal by-products of squid (SBM), tuna (TBM), poultry (PBM) and pork (POBM), and their potential use in diets for Octopus maya were evaluated. Lyophilized crab-meat meal (CRM) (Callinectes sapidus) was used as a reference for the nutritional requirements of the octopus. CRM had the highest crude protein (CP) content (847.2 g kg?1) and the lowest lipid content (27.5 g kg?1). SBM and PBM had more than 700 g kg?1 CP content, while TBM and POBM had less than 600 g kg?1. Lipid content varied between 75.3 (SBM) and 127.2 (PBM) g kg?1. Energy content of CRM was 17.5 MJ kg?1, and the maximum difference with respect to the by-product meals did not exceed 3 MJ kg?1. Amino acid analysis showed that SBM and PBM had high content of Thr, Ser and Ala, which are the most important amino acids for the metabolism of O. maya. Fatty acid analysis showed that they also had a high content of PUFA. PBM showed deficiencies in EPA and DHA content, but had a high content of linoleic acid, which can be a precursor of C:20 and C:22. Based on this, SBM and PBM have nutritional qualities which could be adequate for use as primary protein sources in artificial diets for O. maya