TY - JOUR
T1 - Reproduction and population structure of the sea urchin Heliocidaris crassispina in its newly extended range
T2 - The Oga Peninsula in the Sea of Japan, northeastern Japan
AU - Feng, Wenping
AU - Nakabayashi, Nobuyasu
AU - Narita, Kazumi
AU - Inomata, Eri
AU - Aoki, Masakazu N.
AU - Agatsuma, Yukio
N1 - Funding Information:
The author(s) received no specific funding for this work. We sincerely thank A. Nakamura, the former director general of the Akita Prefectural Institute of Fisheries, for his cooperation with this research. We are grateful to the staff of the Toga Branch of the Akita Fisheries Cooperative Association for their support in collecting sea urchins.
PY - 2019/1
Y1 - 2019/1
N2 - Ocean warming has facilitated the range expansion of commercially important sea urchin species to higher latitudes. Heliocidaris crassispina was recorded to extend northward to Toga Bay along the Oga Peninsula, Japan following an increase in seawater temperatures, and replacement of local sea urchin species Mesocentrotus nudus. In order to identify evidence of adaptation occurring in response to a range extension of H. crassispina to the newly extended environments, we randomly collected 106 H. crassispina in August 2014 in Toga Bay, determined the growth and age composition and examined gonad traits (size, color and development). To confirm the gonad development, 30 H. crassispina with > 30 mm diameter were collected in July, August and September 2017. We found slower growth in the extended range than the central range. More delayed gonad development of males than those of females and a large variety of developmental stages in the acini of testis indicated that the spawning of both sexes of the sea urchins were asynchronous. In terms of gonad color, L* (lightness) values increased with increasing GI, while b* (yellowness) values decreased with increasing age. The population consisted of seven year-classes from 2006 to 2012, suggesting persistent juvenile recruitment. Long-term water temperature data indicated that the range extension of H. crassispina was due to ocean warming, in particular during the summer spawning season.
AB - Ocean warming has facilitated the range expansion of commercially important sea urchin species to higher latitudes. Heliocidaris crassispina was recorded to extend northward to Toga Bay along the Oga Peninsula, Japan following an increase in seawater temperatures, and replacement of local sea urchin species Mesocentrotus nudus. In order to identify evidence of adaptation occurring in response to a range extension of H. crassispina to the newly extended environments, we randomly collected 106 H. crassispina in August 2014 in Toga Bay, determined the growth and age composition and examined gonad traits (size, color and development). To confirm the gonad development, 30 H. crassispina with > 30 mm diameter were collected in July, August and September 2017. We found slower growth in the extended range than the central range. More delayed gonad development of males than those of females and a large variety of developmental stages in the acini of testis indicated that the spawning of both sexes of the sea urchins were asynchronous. In terms of gonad color, L* (lightness) values increased with increasing GI, while b* (yellowness) values decreased with increasing age. The population consisted of seven year-classes from 2006 to 2012, suggesting persistent juvenile recruitment. Long-term water temperature data indicated that the range extension of H. crassispina was due to ocean warming, in particular during the summer spawning season.
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U2 - 10.1371/journal.pone.0209858
DO - 10.1371/journal.pone.0209858
M3 - Article
C2 - 30601863
AN - SCOPUS:85059498753
VL - 14
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 1
M1 - e0209858
ER -