Organogenesis and histological development of the wedge sole Dicologoglossa cuneata M. larva with special reference to the digestive system.

In this work, several features during the wedge sole larval development have been described. The newly hatched larva presented an acidophilic yolk with some oil drops. The digestive tract began to differentiate at 1 DAH, with a loop being discernible. The pancreas and liver were completely formed at 2 DAH, the former showing its typical basophilic acinar structure and acidophilic zymogen granules. The first supranuclear vesicles in enterocytes were seen at 3 DAH. At 4 DAH, yolk reserves were completely exhausted, the number of oesophagus and intestine mucous cells increased, and the heart was differentiated into four chambers: the venous sinus, atrium, ventricle, and arterious bulb. The development was fast and almost all organs were differentiated at 2 DAH. It is important to emphasize that gastric glands were not detected, a factor that should be considered when deciding diet formulation and feeding strategies for the rearing of this species. This work was supported by Interreg Project 0251_ECOAQUA_5_E, financed by the EDRF (European Regional Development Fund). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua. &nbsp;La aced&iacute;a (Dicologoglossa cuneata) es un pez plano comercial objeto de investigaci&oacute;n en el IFAPA Agua del Pino. En este trabajo se describe su desarrollo larvario a nivel histomorfol&oacute;gico. La larva reci&eacute;n eclosionada presenta un saco vitelino con m&uacute;ltiples gotas de grasa, con el ano y la boca cerrados. A nivel histol&oacute;gico, se distingue el tubo digestivo como un segmento tubular recto situado por encima del vitelo. El h&iacute;gado y el p&aacute;ncreas ya est&aacute;n completamente formados a los 2-3 DDE (d&iacute;as despu&eacute;s de la eclosi&oacute;n), y el coraz&oacute;n se diferencia en atrio y ventr&iacute;culo. A los 4 DDE se reabsorbe el vitelo, la larva ya presenta pigmentaci&oacute;n y la boca y ano est&aacute;n abiertos; el tubo digestivo y el coraz&oacute;n se diferencian en 4 regiones, y se observa gran cantidad de t&uacute;bulos renales cerca de la vejiga natatoria. Este &oacute;rgano se insufla entre los 4 y 19 DDE y se atrofia a partir de 20 DDE, coincidiendo con el comienzo de la metamorfosis. El inicio de &eacute;sta se identifica por la transformaci&oacute;n de aleta tipo heterocerca a tipo homocerca, y por la migraci&oacute;n del ojo. La metamorfosis comienza a los 21-31 DDE y finaliza a los 25-37 DDE, por lo que existe una gran asincron&iacute;a.Este trabajo fue apoyado por el proyecto Interreg 0251_ECOAQUA_5_E , financiado por el FEDER (Fondo Europeo de Desarrollo Regional).www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua. &nbsp;</p