Biology Reference
In-Depth Information
Research into the oceanic life of
A. japonica
began late in comparison
with that of Atlantic eels (reviewed by Tsukamoto et al., 2003). The fi rst
leptocephalus was captured in 1967 to the south of Taiwan (Matsui et al.,
Figure 14.
Spawning place and larval migration of Atlantic eels. Both Atlantic eels (
Anguilla
anguilla
and
A. rostrata
) spawn in the Sargasso Sea. Bold grey and black lines indicate the
migration pathways of
A. rostrata
and
A. anguilla
, respectively. Dotted areas are the places
where metamorphosis into glass eel occurs from where they migrate toward estuaries.
1968) and a large number of leptocephali (n=958) were collected in 1991
(Tsukamoto, 1992). After repeated cruises thereafter, the spawning ground
was proposed to be located near a seamount to the west of the Mariana
Islands (Fig. 15). The capture of ripe males and females of
A. japonic
a in
the neighboring area further confi rmed this postulation (Chow et al., 2009;
Tsukamoto et al., 2011). Larvae are considered to be transported by the
North Equatorial Current and then by Kuroshio Current. Metamorphosing
larvae were found in the Kuroshio Current, typically to the east of Taiwan
and to the west of Ryukyu Islands (Tsukamoto, 2006; Otake et al., 2006).
Glass eels move toward the northern Philippines, Taiwan, China, North
and South Korea, and Japan.
3.6.3 Age at metamorphosis
Estimates of the duration of the period of growth up to the glass eel
stage vary widely among different researchers (Table 2). Schmidt (1922)
remarked that
A. rostrata
can complete its full development from egg to
