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Live Specimens Of The Parasite Petrarca Madreporae (Crustacea: Ascothoracida) From The Deep-Water Coral Madrepora Oculata In Japan, With Remarks On The Development Of Its Spectacular Galls, Hiroyuki Tachikawa, Mark J. Grygier, Stephen D. Cairns Feb 2020

Live Specimens Of The Parasite Petrarca Madreporae (Crustacea: Ascothoracida) From The Deep-Water Coral Madrepora Oculata In Japan, With Remarks On The Development Of Its Spectacular Galls, Hiroyuki Tachikawa, Mark J. Grygier, Stephen D. Cairns

Journal of Marine Science and Technology

Grossly enlarged corallites, which had earlier been interpreted as tumors, epibionts, or parasitic galls, on colonies of deep-sea scleractinians of the genus Madrepora from various Indo-Pacific localities, were recognized as galls in 1996 by Grygier and Cairns on account of the new species of ascothoracidan crustacean, Petrarca madreporae Grygier, they had found inside enlarged corallites from a site in Indonesia. Here we report the confirmatory recovery of living specimens of P. madreporae from an enlarged corallite of a possibly undescribed variant of Madrepora oculata Linnaeus in Japan. Two affected coral colonies were taken by fishermen off Katsuura, Chiba Prefecture, at …


Verification Of Echosounder Measurements Of Thickness And Spatial Distribution Of Kelp Forests, Huamei Shao, Kenji Minami, Hokuto Shirakawa, Takashi Maeda, Toshiaki Ohmura, Yoshikazu Fujikawa, Norishige Yotsukura, Masahiro Nakaoka, Kazushi Miyashita Jun 2017

Verification Of Echosounder Measurements Of Thickness And Spatial Distribution Of Kelp Forests, Huamei Shao, Kenji Minami, Hokuto Shirakawa, Takashi Maeda, Toshiaki Ohmura, Yoshikazu Fujikawa, Norishige Yotsukura, Masahiro Nakaoka, Kazushi Miyashita

Journal of Marine Science and Technology

Acoustic methods can be used to assess seaweed meadows. The accuracy of the methods is a key factor in the estimation of seaweed distribution and conditions. We obtained and verified thickness and spatial distribution values measured using an echosounder. We determined the thickness of seaweed growing in the coastal waters off Higashidoori-mura, Aomori, Japan on June 5-6, 2013. Acoustic data were collected using an on-board quantitative echosounder at 120 kHz. The thickness was also directly measured at 14 points. The root mean square error (RMSE) of the thickness determined by the acoustic and direct methods was calculated. A survey to …


Seasonal Dynamics Of Flatfish Assemblage In Coastal Waters Off Northeastern Taiwan: With Implications For Shift In Species Dominance Of The Ecosystem, Shyh-Bin Wang, Wen-Kwen Chen, Shoou-Jeng Joung Dec 2013

Seasonal Dynamics Of Flatfish Assemblage In Coastal Waters Off Northeastern Taiwan: With Implications For Shift In Species Dominance Of The Ecosystem, Shyh-Bin Wang, Wen-Kwen Chen, Shoou-Jeng Joung

Journal of Marine Science and Technology

The seasonal dynamics of flatfish assemblage in the coastal waters off northeastern Taiwan was examined based on samples collected between March 2004 and March 2005 taken by bottom trawlers and landed at Da-Shi fishing port, Yilan county. A total of 28 species from 5 families and 18 genera were found. The Bothidae was the most dominant family, accounting for 81% of the total catch, while the most dominant species was the Pseudorhombus pentophthalmus. Species richness and diversity were high between the end of fall and the end of spring, but low in summer. Multivariate analyses based on cluster and nonparametric …


Age And Growth Study Of The Jack Mackerel (Trachurus Japonicus) In The Northeatern Waters Off Taiwan, Hsueh-Jung Lu, Chih-Chun Chen, Jen-Chia Cheng Dec 2013

Age And Growth Study Of The Jack Mackerel (Trachurus Japonicus) In The Northeatern Waters Off Taiwan, Hsueh-Jung Lu, Chih-Chun Chen, Jen-Chia Cheng

Journal of Marine Science and Technology

Jack mackerel (Trachurus japonicus) is one of the most important fish resources in the northeastern Taiwan. Because of the flourishing of Taiwanese seiner fisheries in recent years, the proportion and catch of jack mackerels have increased. However, the studies on their age and growth are outdated, thus data on the catch-at-age composition are lacking. The present study collected jack mackerel otolith samples from May, 2010, to April, 2011, for age determination and combined those data with length and weight data from 2005 to January, 2012, to investigate the catch-at-age of jack mackerel in the northeastern waters off Taiwan. The regression …


Spatial Estimation Of Euphausiid Biomass Along The Pacific Coast Of Eastern Hokkaido, Japan In Early Summer Of 2008, Naoki Tojo, Kenji Minami, Ryuichi Matsukura, Yohei Kawauchi, Tetsuichiro Funamoto, Masayuki Chimura, Akira Nishimura, Kazushi Miyashita Jun 2011

Spatial Estimation Of Euphausiid Biomass Along The Pacific Coast Of Eastern Hokkaido, Japan In Early Summer Of 2008, Naoki Tojo, Kenji Minami, Ryuichi Matsukura, Yohei Kawauchi, Tetsuichiro Funamoto, Masayuki Chimura, Akira Nishimura, Kazushi Miyashita

Journal of Marine Science and Technology

This study focused on euphausiid distribution and biomass estimation over the coastal shelf of the Pacific coast of Hokkaido Japan in early summer 2008. Acoustic data were obtained in both day (6:00-18:00) and night (18:00-6:00) using a quantitative echosounder (EK60, Simrad) with two frequencies (120 and 38 kHz). Echoes of euphausiids were specified based on the ΔMVBS, calculated with seasonal theoretical target strength of Euphausia pacifica. The best-fit kriging models were used to quantitatively interpolate euphausiid distribution. The detected euphausiid biomass reached 38,278 t (> 15 gWWm-2), suggesting abundant prey for large fishes over study area. On the other hand, …