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Histological development of the digestive system of Mayan cichlid C ichlasoma urophthalmus (Günther 1862)
Author(s) -
CuencaSoria C. A.,
ÁlvarezGonzález C. A.,
OrtizGalindo J. L.,
TovarRamírez D.,
GuerreroZárate R.,
AguilarHernández S.,
PereraGarcía M. A.,
HernándezGómez R.,
Gisbert E.
Publication year - 2013
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/jai.12307
Subject(s) - biology , hatching , yolk sac , stomach , ontogeny , anatomy , yolk , digestive tract , gastric glands , medicine , endocrinology , embryo , gastric mucosa , ecology , fishery , biochemistry
Summary The ontogeny of the digestive tract in C ichlasoma urophthalmus was studied by means of optical microscopy from hatching to 30 days post‐hatching (dph; 855 degree days, dd). The development of the digestive system in this precocial species was a very intense and asynchronous process, which proceeded from both distal ends interiorly. At hatching, the digestive tract consisted of a straight tube with a smooth lumen dorsally attached to the yolk‐sac. The digestive accessory glands were already differentiated and eosinophilic zymogen granules were visible in the exocrine pancreas. At the onset of exogenous feeding between 5 and 6 dph (142.5–171.0 cumulative thermal units, CTU ), the buccopharynx, oesophagus, intestine, liver and pancreas were almost completely differentiated, with the exception of the gastric stomach that completed its differentiation between 11 and 14 dph (313.5–399.0 CTU ). The development of gastric glands at 14 dph and the differentiation of the stomach in the fundic, cardiac and pyloric regions at 19 dph (541.5 CTU ) were the last major events in digestive tract development and designated the onset of the juvenile period. Remnants of yolk were still detected until 16 dph (456.0 CTU ), indicating a long period of mixed nutrition that lasted between 10 and 11 days (285.0–313.5 CTU ). The results of the organogenesis of larvae complement previous data on the functionality of the digestive system and represent a useful tool for establishing the functional systemic capabilities and physiological requirements of larvae to ensure optimal welfare and growth under aquaculture conditions, which might be useful for improving current larval rearing practices for this cichlid species.