Larval Konosirus punctatus(Clupeidae) in a brackish river mouth on the Pacific coast of central Japan

Abstract

Eggs of Konosirus punctatus in early developmental stages were collected from the eastern part of the mouth of Sagami Bay on the Pacific coast of central Japan. Advanced‐stage eggs and early larvae with notochord length (LN) of <7·5 mm were collected from the inner bay near the mouth of the Sagami River. Feeding larvae of >8·4 mm LN were distributed in the mouth of the river, and juveniles of 24–90 mm standard length (LS) were collected from the lower reaches of the river between the river mouth and c. 3 km upstream of the river mouth. Hatch dates of larvae and juveniles collected in 2001 (n = 158) and in 2002 (n = 109) extended from late March to late July. The relationship between the otolith radius (RO) and LN or LS changed during the metamorphosis stage as characterized by 320 μm RO and 22 mm LS. Otolith growth rate, as an index of somatic growth rates in larval and early juvenile stages, was higher in cohorts that hatched later in the spawning season, i.e. from March to July. Konosirus punctatus that were spawned in the bay mouth area survived with different growth histories in the bay and lower reaches of the river, and recruited to the young‐of‐year population in the Pacific coastal waters of central Japan.

Early life history of <i>Ilisha elongata</i> (Pristigasteridae, Clupeiformes, Pisces) in Ariake Sound, Shimabara Bay, Japan

“…The early life histories of the engraulid C. nasus and the clupeid S. zunasi, both of which are abundant in summer, have been studied in Ariake Sound (Takita 1966, Ishida & Tsukahara 1972, Yagi 2010, Simanjuntak et al 2015, Simanjuntak 2016, Ito et al 2018. The eggs and larvae of the clupeid K. punctatus are present from late winter to early summer in various waters in Japan and the Korean Peninsula, but they have not been reported in Ariake Sound (Yoshida 1937, Matsushita & Nose 1974, Kawasaki et al 2006. Although the reproductive ecology of I. elongata has been examined in Ariake Sound and the Seto Inland Sea (Zhang & Takita 2007, Zhang et al 2009, Masui et al 2016, its early life history has only been investigated sporadically in the Geum estuary in western Korea, around the Hangzhou estuary in central China, and in Ariake Sound.…”

Comprehensive phylogeny of Konosirus punctatus (Clupeiformes: Clupeidae) based on transcriptomic data

“…Previous studies also showed that it is a native species in the northwest Pacific Ocean and supports important commercial fisheries, especially juveniles with total length of 10–15 cm [ 4 ]. Recently, this fishery resource was highly overfished for human consumption resulting in its decline compared with historical fishery resource data [ 4 ]. Furthermore, due to high market demand and ecological value, the culture of K. punctatus have developed rapidly in the past decades.…”

“…For instance, the ingestion, growth and survival of K. punctatus often have been severely affected by the low temperature stresses, indicating that this species is adaptive to warm water. Meanwhile, some researchers suspected that K. punctatus has a tendency to migrate to brackish waters during reproduction stages and therefore the reproduction behavior might be associated with seawater salinity [ 4 ]. However, limited evidences were applied to discuss the relevant regulatory mechanism of K. punctatus at the genetic level.…”

Comparison of larval distribution in two clupeoid fishes (<i>Ilisha elongata</i> and <i>Sardinella zunasi</i>) in the inner estuaries of Ariake Sound, Shimabara Bay, Japan

“…Although there is considerable information about the early life history of C. nasus (Takita 1967, Ishida & Tsukahara 1972, Yagi 2010, Simanjuntak et al 2015, Simanjuntak 2016, Ito et al 2018, K. punctatus (Yoshida 1937, Matsushita & Nose 1974, Kawasaki et al 2006, Yagi 2010) and S. zunasi (Takita 1966, Yagi 2010 in Ariake Sound and other Japanese waters, only Yagi (2010) has examined the life history of I. elongata. When we examined the egg and larva distributions of this species in the Ariake Sound, we found that I. elongata and S. zunasi larvae have almost the same life history patterns and a sympatric distribution in the estuary.…”