Book chapter
Chapter 11 - Octopus tetricus, gloomy octopus
Octopus Biology and Ecology, pp.177-185
Academic Press
07/06/2024
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Abstract
Octopus tetricus, the gloomy octopus, is common in Oceania coastal waters of south-eastern Australia and north-eastern New Zealand; it was recently split from a Western Australian sister taxon, O. djinda. Octopus tetricus has undergone a poleward range extension into north-eastern Tasmania, Australia in response to climate change. Although small numbers are trawled out to 70 m depth, it mainly inhabits shallow seagrass beds, coastal rocky reefs, and large bays and estuaries. Octopus tetricus is a medium-sized species with a maximum armspan of up to 2 m and weighs up to 2.6 kg. Life history information is limited and available mainly from two temperate locations at the extremity of the species’ distribution, Tasmania and New Zealand, where maximum lifespans range from 11 months to 2 years, respectively. Like other merobenthic octopuses, it is highly fecund, laying up to 267,581 small eggs (2.2–2.5 mm long and 1 mm wide) per female in long bunches that hatch into planktonic paralarvae (2.2–4 mm total length) after 24–65 days development, with duration negatively correlated with water temperature. Adults prey on shellfish and crustaceans and in turn provide a food source for many commercially important finfish and elasmobranchs. At two dense, localized aggregations in New South Wales, Australia interactions occur between conspecifics during daylight, which is unusual not only for O. tetricus elsewhere (e.g. New Zealand), but for octopus worldwide, given that many species are considered solitary and nocturnal or crepuscular. The species has also provided a fascinating laboratory case study for cephalopod vision and personality trait studies. More information on the biology and ecology of the species from the central area of the species’ distribution on mainland south-eastern Australia is required to ensure sustainable management of these exploited populations, especially given recent shifts towards targeted, rather than incidental, by-product fisheries for the species.
Details
- Title
- Chapter 11 - Octopus tetricus, gloomy octopus
- Creators
- Karina C. Hall - New South Wales Department of Primary Industries (Port Stephens)Natalie A. Moltschaniwskyj - New South Wales Department of Primary Industries (Port Stephens)
- Contributors
- Rui Rosa (Editor of compilation) - University of LisbonIan G Gleadall (Editor of compilation) - AiCeph LLC (Japan, Sendai)Graham J. Pierce (Editor of compilation) - Consejo Superior de Investigaciones CientíficasRoger Villanueva (Editor of compilation) - Institut de Ciències del Mar
- Publication Details
- Octopus Biology and Ecology, pp.177-185
- Publisher
- Academic Press; London, UK
- Identifiers
- 991013384452202368
- Copyright
- © 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
- Academic Unit
- Faculty of Science and Engineering
- Language
- English
- Resource Type
- Book chapter