Patagonian toothfish catch by Argenova XIV. Photo: INIDEP
Fifteen years of liberty for a Patagonian toothfish marked in the Argentine Sea
ARGENTINA
Thursday, July 16, 2026, 00:10 (GMT + 9)
The INIDEP registers a historic record of permanence and reveals disparate migratory behaviors in the species through three specimens recaptured by the commercial fleet.
The Patagonian toothfish (Dissostichus eleginoides) tagging and recapture program carried out by the National Institute for Fisheries Research and Development (INIDEP) has achieved an unprecedented scientific milestone in the Argentine Sea. As reported by Revista Puerto, after processing recent catches from the commercial fleet, researchers documented the case of a male specimen that remained at liberty for fifteen years, representing the longest period of permanence recorded to date for this species under this study system.
This historic finding is complemented by information obtained from two other specimens recovered in recent weeks. The joint analysis of these cases confirms one of the institute's main hypotheses: while some individuals show strict fidelity to their residence areas, others make large-scale movements along the continental slope.
Source: Revista Puerto
The record-breaking specimen had been tagged and released by scientists in 2011 over the northern Argentine slope. At that time, the fish measured 74 centimeters in total length and weighed less than 4 kilograms. Fifteen years later, last month, the longliner Centurión del Atlántico recaptured it near Isla de los Estados, at the southern extreme of its distribution in national waters. At the time of its recovery, the Patagonian toothfish had reached 140 centimeters in length and a weight of 23.3 kilograms. This case not only establishes a time record but also directly validates growth rates and the reading of growth rings in otoliths, a key tool for resource assessment.
Source: Revista Puerto
In contrast, the other two reported cases demonstrate the sedentary behavior of the species. The first of these, detailed by Revista Puerto on June 10, 2026, corresponds to a specimen that had been captured and tagged on May 12, 2013, at a depth of 1054 meters off the Province of Buenos Aires. On June 6 last, after more than thirteen years at liberty, it was recaptured by a commercial vessel just 62 kilometers away from its original release point. The third specimen, released in 2018 in the northern sector of the slope, was recently recovered by the longliner Argenova XIV in an area very close to its coordinate of origin, reflecting a continuous permanence in its residence area for approximately eight years.
Source: INIDEP
In Argentina it is known as merluza negra, but in other countries it is known by different names, such as bacalao de profundidad (Chile and Spain), mero (Japan, commercially), Klykach (Russia) and Patagonian toothfish or Chilean seabass (English-speaking countries). In official Spanish terminology (CCAMLR/FAO) it is designated as austromerluza negra
Source: INIDEP
Since the start of this research program in 2004, INIDEP has managed to tag and release a total of 6009 specimens of Patagonian toothfish, of which 122 have been recaptured. Historical data reveal that most individuals are usually found less than 100 kilometers from the tagging location, even after almost three years at sea, although a minority has registered movements exceeding 3000 kilometers in similar periods.
Source: COLTO
The continuity and strengthening of these investigations will be supported by the recent repair and full reinstatement to fishing operations of the vessel Argenova XIV, which is currently positioned as the only active longliner of the Argentine fleet dedicated exclusively to this fishery. Cooperation between the institute, shipowning companies, captains, crews, and scientific observers on board is indispensable to ensure the collection of these tags and guarantee the sustainable exploitation of this highly long-lived resource, capable of exceeding fifty years of age in the deep seas.
記録を樹立した個体は、2011年にアルゼンチン北部の斜面海域で研究者によって標識放流されました。当時、この魚は全長74センチメートル、体重4キログラム未満でした。それから15年が経過した先月、はえ縄漁船Centurión del Atlánticoが、領海内の分布南端にあたるエスタードス島近海でこの個体を再捕しました。回収時、このマジェランアイナメは全長140センチメートル、体重23.3キログラムに達していました。この事例は期間の記録を樹立しただけでなく、成長率を直接実証し、資源評価の重要なツールである耳石の成長輪の読み取りを検証することを可能にしました。
创下纪录的这尾个体于2011年在阿根廷北部陆坡被科研人员标记并放流。当时,这尾鱼的全长为74厘米,体重不足4公斤。十五年后的上个月,延绳钓渔船Centurión del Atlántico在靠近国家领水分布南端的埃斯塔多斯岛附近海域将其重新捕获。在回收时,这尾小鳞犬牙南极鱼的全长已达到140厘米,体重达23.3公斤。这一案例不仅确立了时间记录,还直接验证了生长率以及耳石生长轮的读取结果,这是评估该资源状况的关键工具。