TY - JOUR
T1 - Fine structure and differentiation of the alimentary canal in captive-bred Japanese eel Anguilla japonica preleptocephali
AU - Ozaki, Yuichi
AU - Tanaka, Hideki
AU - Kagawa, Hirohiko
AU - Ohta, Hiromi
AU - Adachi, Shinji
AU - Yamauchi, Kohei
PY - 2006/2/1
Y1 - 2006/2/1
N2 - The fine structure of the alimentary canal in preleptocephali produced by artificially matured Japanese eel was examined. At 1 day posthatch (dph), the alimentary canal was found only above the dorsal side of the yolk mass, and the epithelium was composed of a single layer of epithelial cells. By 5 dph, the alimentary canal was divided into three segments based on the structure of the epithelial cells: foregut, midgut and hindgut, corresponding to the future esophagus, intestine and rectum, respectively. After 7 dph, the epithelium in the foregut was surrounded by a circular muscle layer, suggesting a role in the transportation of food materials. The epithelial cells of the midgut exhibited well-developed membranous structures, which are deduced to be invaginations of the cytoplasmic membrane. Pinocytotic invaginations and vacuoles were observed in the epithelial cells of the hindgut; this observation suggests that this region is involved in the uptake of food. Significant changes in morphological features of the epithelial cells in each segment were observed until 7 dph; however, these were not evident between 7 dph and 13 dph. Consequently, the differentiation of the alimentary canal was completed by 7 dph, and preleptocephalus had developed the ability to absorb food by 7 dph.
AB - The fine structure of the alimentary canal in preleptocephali produced by artificially matured Japanese eel was examined. At 1 day posthatch (dph), the alimentary canal was found only above the dorsal side of the yolk mass, and the epithelium was composed of a single layer of epithelial cells. By 5 dph, the alimentary canal was divided into three segments based on the structure of the epithelial cells: foregut, midgut and hindgut, corresponding to the future esophagus, intestine and rectum, respectively. After 7 dph, the epithelium in the foregut was surrounded by a circular muscle layer, suggesting a role in the transportation of food materials. The epithelial cells of the midgut exhibited well-developed membranous structures, which are deduced to be invaginations of the cytoplasmic membrane. Pinocytotic invaginations and vacuoles were observed in the epithelial cells of the hindgut; this observation suggests that this region is involved in the uptake of food. Significant changes in morphological features of the epithelial cells in each segment were observed until 7 dph; however, these were not evident between 7 dph and 13 dph. Consequently, the differentiation of the alimentary canal was completed by 7 dph, and preleptocephalus had developed the ability to absorb food by 7 dph.
KW - Alimentary canal
KW - Fine structure
KW - Japanese eel
KW - Preleptocephalus
UR - http://www.scopus.com/inward/record.url?scp=33645060779&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33645060779&partnerID=8YFLogxK
U2 - 10.1111/j.1444-2906.2006.01110.x
DO - 10.1111/j.1444-2906.2006.01110.x
M3 - Article
AN - SCOPUS:33645060779
VL - 72
SP - 13
EP - 19
JO - Fisheries Science
JF - Fisheries Science
SN - 0919-9268
IS - 1
ER -