selectividad duorarum 10.1111-j.1753-5131.2012.01081.x

Selectivity of particle size by the pink shrimp Farfantepenaeus duorarum (Burkenroad, 1939) larvae Rolando Gelabert and Roberto Brito Research Center of Environmental Sciences, Faculty of Natural Sciences, Autonomous University of Carmen, City of Carmen, Campeche, Mexico Introduction One of the three native penaeid shrimp species of com- mercial importance living along the southern Atlantic and Gulf coasts of the United States and Mexico is the pink shrimp Farfantepe naeus duorarum. Th is sp ecies, alon g with the white shrimp Litopenaeus setiferus and the brown shrimp F. aztecus, not only support the economy of the shrimp industry but also play an important role in recrea- tional and sport fishing (Waters et al. 2006). The shr imp aquacu ltu re ind ust ry is les s dev elo ped in the Gulf of Mexico than along the Mexican Pacific coast, tho ugh in rec ent yea rs the federa l gov ernmen t has bee n drivi ng the development of aquacult ure in the southern Gulf of Mexi co. Conc ern and legal pressure s asso ciat ed wit h the int roduct ion of Litopenaeus vannamei to non - nat ive areas are the most limiti ng fac tors hal tin g the dev elo pme nt of shr imp aquacu ltu re in thi s reg ion. In rec ent yea rs the rel at ive impor ta nce of the cul tur e of F. duorarum has increased because their populations have sho wn sig ns of deplet ion and bec aus e of the inc rea sin g interest in developing culture techniques for native species (Araos-Dzul et al. 2000; Gullian et al. 2010). In aquaculture systems there is not always enough live food to guarantee a high production of larvae, so formu- lated feeds pla y an imp ort ant role in the semiintensi ve production of shrimp. These feeds now constitute nearly 55% of the tot al operat ing cost (Mo han ty 200 1). The information reviewed suggests it is necessary for the food producer carefully to handle not only the ingredients to support the appropriate nutritional value and the stability in the water of the artificial food, but also its size. The uningested food sinks to the bottom of the culture tank and neg at ive ly imp act s the wat er qua lit y. The cost of Correspondence Rolando Gelabert, Centro de Investigacio ´ n de Ciencias Ambientales, Dependencia de Educacio ´ n Superior de Ciencias Naturales, Universidad Auto ´ noma del Carmen, Ciudad del Carmen, Campeche, Me ´ xico. Email: rgelabert@pa mpano.un acar.mx Received 13 July 2011; accepted 8 June 2012. Abstract Artificial foods have been proposed in aquaculture as a complement or substi- tute for live food and the quality has been evaluated by considering nutritional value , accep tabi lity, digesti bili ty and wate r stab ilit y, but because of the filter - feeding behaviour of larvae of the cultured shrimp and the diversity of food found in the market for larviculture, it is important to define the size of food ingested by the different larval stages until the postlarval stage where raptorial habits are more evident than the filter feeding lifestyle. Selectivity assays in the pink shrim p Farfantepenaeus duorarum larvae wer e ma de usi ng pol yst yre ne DVB parti cle s with a dia met er bet ween 1 and 50 lm as food. A group of organisms between zoea I and postlarval I stages were put into the particle sus- pension for 15 min to let the particles be ingested. The particle distribution in the medium and the content of the gut of the animals were characterized with digi tal-i mage process ing analy sis. The resul ts were compared using the Ivlev selectivity formula, which contrasts the frequency distribution of each particle siz e in the me dium and in the gut of larva e. The resul ts of sel ect ivi ty were adjusted with a third-order polynomial regression to determine the optimum and the preferred size of the food for each larval stage. The optimum sizes of the food ing est ed for the dif ferent sta ges of F. duorarum were between 6.17 and 12.02 lm and the preferred were found to be between 2.68 and 18.65 lm. Key words: feeding, larvae, particle size, selectivity, shrimp . Reviews in Aquaculture (2013) 5, 72–76 doi: 10.1111/j.1753-5131.2012.01081.x 72 ª 2013 Blackwell Publishing Asia Pty Ltd

selectividad duorarum 10.1111-j.1753-5131.2012.01081.x

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