Pub Date : 2023-12-29DOI: 10.1134/s0032945224010132
D. G. Kim, H. Y. Soh, G. W. Baeck
Abstract
Feeding habits and trophic level of juvenile greater amberjack, Seriola dumerili were studied using 170 specimens collected by set net fishery and lure fishing in the southern waters of Korea during July, August, September, October, and November 2022. The size of juvenile greater amberjack ranged from 17.5 to 49.9 cm in fork length. Juvenile greater amberjack was piscivorous predator that feed primarily on fish. We calculated the trophic level as 4.06 ± 0.80 for juvenile greater amberjack. Fishes were the main prey items for all size groups. Juvenile greater amberjack also showed size-related dietary shift from Japanese anchovy to jack mackerel. As the fork length of juvenile greater amberjack increase, the mean weight of prey per stomach tended to increased, while the mean number of preys per stomach was not significantly different. Fishes were the main prey items for summer and autumn. The main fish prey during summer and autumn was Japanese anchovy, but in the autumn, the Japanese anchovy portion decreased, and the jack mackerel portion increased. PERMANOVA analysis was used to examine seasonal and size-related changes in diet composition, which showed significant variations among size classes. Juvenile greater amberjack presumably feed on larger prey to meet their energy requirements.
{"title":"Feeding Habits and Trophic Level of Juvenile Greater Amberjack, Seriola dumereili (Carangidae) in the Southern Waters of Korea","authors":"D. G. Kim, H. Y. Soh, G. W. Baeck","doi":"10.1134/s0032945224010132","DOIUrl":"https://doi.org/10.1134/s0032945224010132","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Feeding habits and trophic level of juvenile greater amberjack, <i>Seriola dumerili</i> were studied using 170 specimens collected by set net fishery and lure fishing in the southern waters of Korea during July, August, September, October, and November 2022. The size of juvenile greater amberjack ranged from 17.5 to 49.9 cm in fork length. Juvenile greater amberjack was piscivorous predator that feed primarily on fish. We calculated the trophic level as 4.06 ± 0.80 for juvenile greater amberjack. Fishes were the main prey items for all size groups. Juvenile greater amberjack also showed size-related dietary shift from Japanese anchovy to jack mackerel. As the fork length of juvenile greater amberjack increase, the mean weight of prey per stomach tended to increased, while the mean number of preys per stomach was not significantly different. Fishes were the main prey items for summer and autumn. The main fish prey during summer and autumn was Japanese anchovy, but in the autumn, the Japanese anchovy portion decreased, and the jack mackerel portion increased. PERMANOVA analysis was used to examine seasonal and size-related changes in diet composition, which showed significant variations among size classes. Juvenile greater amberjack presumably feed on larger prey to meet their energy requirements.</p>","PeriodicalId":48537,"journal":{"name":"Journal of Ichthyology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139067088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.1134/s0032945224010144
T. P. Malyshkina, M. V. Nazarkin, A. V. Solovyow
Abstract
An isolate tooth of a rare extinct hook-toothed mako Cosmopolitodus planus (Agassiz, 1856), discovered in the Lower Miocene deposits of the Chekhov Formation of Sakhalin Island is described. This extinct species was distributed exceptionally in the Pacific basin, and is known mainly from the deposits of the Middle and Upper Miocene. Thus, the described tooth is, probably, the oldest record of this species. The geographic and stratigraphic distribution of this species, as well as the validity of the genus Cosmopolitodus Glickman, 1964, are discussed.
{"title":"An Oldest Record of the Shark Cosmopolitodus planus (Lamnidae) from the Lower Miocene of the Sakhalin, Russia","authors":"T. P. Malyshkina, M. V. Nazarkin, A. V. Solovyow","doi":"10.1134/s0032945224010144","DOIUrl":"https://doi.org/10.1134/s0032945224010144","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>An isolate tooth of a rare extinct hook-toothed mako <i>Cosmopolitodus planus</i> (Agassiz, 1856), discovered in the Lower Miocene deposits of the Chekhov Formation of Sakhalin Island is described. This extinct species was distributed exceptionally in the Pacific basin, and is known mainly from the deposits of the Middle and Upper Miocene. Thus, the described tooth is, probably, the oldest record of this species. The geographic and stratigraphic distribution of this species, as well as the validity of the genus <i>Cosmopolitodus</i> Glickman, 1964, are discussed.</p>","PeriodicalId":48537,"journal":{"name":"Journal of Ichthyology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139066865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}