The larval attachment organ of the Tropical Gar Atractosteus tropicus Gill, 1863 (Lepisosteiformes: Lepisosteidae)

Tropical gar, Atractosteus tropicus Gill, 1863, is an ancient freshwater fish that is commercially cultivated in southern Mexico. Currently, there is a specific diet for its culture; however, the addition of probiotics has not been investigated. The objective of this study was to evaluate the supplementation of live yeast Debaryomyces hansenii for A. tropicus juveniles on growth, productive parameters, survival, somatic index, digestive enzyme activity, and immune system gene expressions (interleukin 10, il-10, Transforming growth factor β1, tgf-β1, and β2 microglobulin, b2m). Three experimental diets increased the dose of live yeast (0.5, 1.0, and 1.5%; 1014, 1015, and 1016CFU g diet–1, respectively) and a control diet (CD; without yeast) were designed. Daily weight gain and specific growth rate were higher in fish fed with CD and 0.5% D. hansenii. High activities of trypsin, chymotrypsin LAP, and α-amylase, as well as overexpression of il-10 in the spleen, were detected in fish feed 0.5% D. hansenii. The inclusion of D. hansenii had no positive effect on aquaculture for A. tropicus, lower doses should be tested to optimize the diet.

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Evaluación de alimentos microencapsulados en el cultivo de larvas de pejelagarto (Atractosteus tropicus)

Revista de Biología Tropical ◽

10.15517/rbt.v66i3.31727 ◽

2018 ◽

Vol 66 (3) ◽

pp. 1298

Author(s):

Miguel Saenz de Rodrigáñez ◽

Federico Vladymir Aguilar-Tellez ◽

Francisco Javier Alarcón-López ◽

Ruth Pedrosa-Islas ◽

Emyr Saul Peña-Marín ◽

...

Keyword(s):

Enzyme Preparation ◽

Fish Meal ◽

Control Diet ◽

Control Treatment ◽

Nannochloropsis Gaditana ◽

Growth And Survival ◽

Artemia Nauplii ◽

Design And Manufacturing ◽

Tropical Gar ◽

Atractosteus Tropicus

Four microencapsulated diets were evaluated with respect to the growth and survival of tropical gar Atractosteus tropicus larvae. The treatments consisted of four experimental diets and one control diet 1) fish meal, 2) a combination of pork and poultry meals, 3) Nannochloropsis gaditana meal, 4) enzyme preparation and the control treatment 5) Artemia nauplii. The evaluation indicated that the larvae fed the Artemia nauplii obtained the greatest growth and survival (3.93 cm, 0.19 g y 82 % respectively), which justifies a correct culture system operation. While larvae fed microencapsulated diets best values in survival were observed with diets Nannochloropsis gaditana and enzyme preparation (20.0 and 19.2 %). Our results showed that microencapsulated could be used to feed A. tropicus in feasibly form. However, more information concerning to optimize the design and manufacturing are required to improve the growth and survival of organisms.

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High-throughput sequencing of the 16S rRNA gene to analyze the gut microbiome in juvenile and adult tropical gar (Atractosteus tropicus)

Latin American Journal of Aquatic Research ◽

10.3856/vol48-issue3-fulltext-2419 ◽

2020 ◽

Vol 48 (3) ◽

pp. 456-479

Author(s):

Roberto Méndez-Pérez ◽

Rodrigo García-López ◽

J. Santiago Bautista-López Bautista-López ◽

Jorge Vázquez-Castellanos ◽

Carlos Alvarez-González ◽

...

Keyword(s):

Gut Microbiota ◽

Gut Microbiome ◽

Aeromonas Hydrophila ◽

Phylogenetic Trees ◽

Gut Contents ◽

Estuarine Fish ◽

Rrna Gene ◽

Wild Type ◽

Tropical Gar ◽

Atractosteus Tropicus

Tropical gar (Atractosteus tropicus) is freshwater and estuarine fish, inhabiting the Earth since the Mesozoic era and undergoing limited physiological variation ever since. Besides its recognized cultural andscientific relevance, the species has seen remarkable growth in its economic impact due to pisciculture. In this study, we present the first report of the whole taxonomic composition of microbial communities in gut contents in juveniles and adults of A. tropicus, by sex and origin (wild and cultivated). For this study, 508 genera were identified, with the most and least abundant being Cetobacterium and Paludibacter, respectively. Fusobacteria, Proteobacteria, Firmicutes, and Bacteroidetes phyla are the core gut microbiome of A. tropicus juvenile and adult by sex and origin. Deinococcus-Thermus phylum sequence was only identified in wild-type males. In the phylogenetic trees reconstruction Lactococcus lactis strains CAU929 and CAU6600, Cp6 and CAU9951,Cetobacterium strain H69, Aeromonas hydrophila strain P5 and WR-5-3-2, Aeromonas sobria strain CP DC28 and Aeromonas hydrophila were identified, some of them with probiotic potential within the three dominant phyla in core gut microbiome in A. tropicus adults, especially in wild-type organisms. Myroides genus was recognized in microbiota gut of the cultivated juvenile A. tropicus. Nevertheless, Alpha diversity indicated that the highest gut microbiota abundance and richness is found in cultivated juvenile and wild-type adult A. tropicus female, rather than adult wild-type males and the least gut microbiota abundance and richness is found in a cultivated adult of A. tropicus for both sexes.

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