• Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.158-166
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• 2022

The complete mitochondrial genome of Tremoctopus violaceus was sequenced to analyze its organization and phylogenetic status within the order Octopoda. The mitochondrial genome of T. violaceus had a structure and organization similar to that of other Octopoda. The content of the nucleotides A, C, G, and T was 31.68 %, 7.71 %, 20.02 %, and 40.58 %, respectively. All protein-coding genes (PCG) began with the ATG codon, excluding ND4 and ATP6, which began with ATC and ATT, respectively, and terminated with TAG, TAA, TA, or T. Codons for isoleucine were the most used codons, whereas those for arginine were used the least. Two extra tRNAs, trnN and trnL, were found in the control region. These tRNAs have a D-armless structure. The control region had excess A + T content (83.16 %) and a stem-loop structure with two elements, which is reported for the first time in Octopoda by our study. Bayesian inference using 13 PCG revealed that Octopus and Octopodidae were polyphyletic, and that Tremoctopodidae diverged relatively earlier within Octopoda. The mitochondrial genome of T. violaceus and its characteristics may help to understand the evolutionary history of Octopoda and establish a marine biodiversity conservation strategy.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.171-175
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• 2010

Korean cephalopods only recorded with Korean name in the literature were reviewed to solve confusions in use of their Korean name for taxonomic studies of cephalopods in Korea, and to prepare a basic check list for standardizing total cephaolopods fauna of Korea in the future. A total 38 cephalopods species with Korean names were listed in this study; 14 species in order Sepioidea, 17 species in Teuthoidea, 7 species in Octopoda. The etymology and some problems of Korean names of cephalopods occurring in Korea, and the useable rules for naming cephalopods with Korean words are recommended and discussed.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.35-36
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• 2000

낙지, Octopus variabilis, 는 연체동물 중 두족강의 신두족강(Neocephaloda) 팔완목(Octopoda)에 속하고, 주로 우리 나라의 서해안과 남해안을 비롯하여 일본과 중국의 연근해까지 널리 분포하고 있는 연안성ㆍ천해성ㆍ난해성 수족으로서, 연안의 해저 바닥이 뻘로 된 곳에 주로 분포하기 때문에, 낙지어획은 주로 주낙, 기선 저인망, 통발 등에 의해 이루어져 왔는데, 그 중에서 주낙에 의한 어획량이 가장 많다. 그러나 낙지 어업에 대해서는 지금까지 어장학적 연구가 전혀 이루어지지 않았고, 어민들의 경험에만 의존하여 행해지고 있는 실정이다. (중략)

• The Korean Journal of Malacology
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• v.32 no.1
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• pp.55-62
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• 2016

In this study, an attempt has been made to analyze the morphology of Cephalopods distributed in Korea and collected samples from South-East Asian countries including Thailand, Indonesia, Vietnam, and China. A phylogenetic analysis was performed using the mitochondrial gene, Cytochrome c oxidase subunit I (COI) to understand the genetic divergences of the species and validate their origins. For achieving the objectives, samples were collected directly from Thailand Hat Yai, Songkhla, Indonesia Medan, Vietnam Ho Chi Minh, and Vung Tau in August 2015 and from China in September 2015. A total of 23 species of Cephalopods were identified falling under three orders, four familyies and nine genus. The species were distributed under Order: Octopoda (1 family, 3 genus, and 9 species), Order: Sepiolioda (1 family, 2 genus, and 8 species), and Order Teuthoidea (2 family, 4 genus, and 6 species). 23 species which is 1 family 3 genus 9 species in Octopoda, 1 family 2 genus 8 species in Sepiolioda, 2 family 4 genus 6 species in Teuthoidea. Phylogenetic analysis using COI gene was conducted for 18 species. For the remaining 5 species sequencing results showed severe variation and hence were not considered further. The COI phylogenetic analysis for the 18 species of Cephalopods were found consistent with the morphological identification. The excluded species will be subjected for a further detailed analysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.4
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• pp.243-247
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• 2007

We investigated the reproductive behavior of Octopus minor, order Octopoda, class Cephalopoda under laboratory conditions. Each mature female octopus was kept in an aquarium with a plastic tube for shelter, and one mature male was introduced for the purpose of copulation. Before spawning, the female coated the roof of the shelter with a light-green material, upon which it then fixed its eggs one by one. This spawning behavior lasted 1 to 3 days. Fertilized females spawned 54 eggs on average, ranging from 21 to 112 eggs at 72 to 98 days after copulation. The attached eggs were 18.1-19.0 mm in length, 5.0-6.1 mm in width, and 0.30-0.38 g in weight. The mother octopods did not feed; they attended to the eggs by using their arms to rub the egg surfaces and used their funnel to blow sediments off of the eggs. At water temperatures of $20.9-21.5^{\circ}C$, the fertilized eggs hatched within 73 to 90 days after being spawned. The effective cumulative water temperature was $1,569-1,892^{\circ}C$. At the end of incubation, the body weight of the mother octopods was reduced to approximately 56% of the initial weight, and most mother octopods died soon after the young hatched.