Biology Reference
In-Depth Information
Fully grown leptocephali reached 50-60 mm in length approximately
250 days after hatching and then commenced metamorphosis (Fig. 8). During
metamorphosis, the positions of the anus, and of the anterior edges of the
dorsal and anal fi ns, moved forward. Body depth was drastically reduced.
Black pigment and the color of the blood became visible. Metamorphosis
was completed within about 2 weeks. The development of digestive
system was examined using artifi cially produced leptocephali (Kurokawa
et al., 1995; Kurokawa et al., 1996; Kurokawa and Pedersen, 2003). The
segmentation of the gut into the esophagus, intestine and rectum, together
with the synthesis of pancreatic the digestive enzymes trypsin, amylase, and
Figure 8.
Morphological changes in larval and metamorphosing Japanese eel (
Anguilla japonica
).
Live larvae were photographed. Fish at stages from hatching to 200 days are representatives
of reared fi sh. Metamorphosing fi sh from 260-269 days were the same individual. Provided
from Dr. Tanaka.
