Thymops

Thymops birsteini, the Patagonian lobsterette, is a species of lobster found around the coasts of South America, particularly the South Atlantic. It belongs to the monotypic genus Thymops.

Thymops birsteini
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Family: Nephropidae
Genus: Thymops
Holthuis, 1974 [2]
Species:
T. birsteini
Binomial name
Thymops birsteini
(Zarenkov & Semenov, 1972) [3]
Synonyms[4]

Nephropides birsteini Zarenkov & Semenov, 1972

Distribution

T. birsteini is found on the continental shelf around South America, particularly in the Argentine Sea. In the Atlantic Ocean, it is found south of 37° south, with Uruguay representing the northern extremity of its distribution;[5] on the Chilean (Pacific) side, it is found south of 51° south.[4] Its range includes the areas around the Falkland Islands (Islas Malvinas) and areas near South Georgia, extending as far south as 57°, close to the Antarctic Peninsula.[6] It lives at depths of 120–1,500 metres (390–4,920 ft).[7]

Description

T. birsteini resembles a typical lobster, with two large claws, four other pairs of pereiopods, and a long pleon (tail). The carapace is granular, especially in the front half, and it bears a rostrum which divides into two points at its tip.[7] The total length may range from 8 to 25 centimetres (3.1 to 9.8 in), with the carapace being 2–10 cm (0.79–3.94 in) long.[4] Smaller individuals are found in shallower waters, and larger individuals are found at greater depths (up to 1,400 m or 4,600 ft).[8] There is also latitudinal variation in colour, with northern individuals being pale yellow, while those from further south are maroon.[7]

Ecology

Little is known about the biological interactions of T. birsteini. It is occasionally eaten by the Patagonian toothfish Dissostichus eleginoides.[9] It seems to prefer muddy bottoms, and has been observed entering and exiting burrows.[10]

Life cycle

As in other pleocyemates, T. birsteini broods its eggs on the female's pleopods. One female may carry up to 380 eggs, each 1.5–1.9 millimetres (0.059–0.075 in) in diameter. The eggs grow as they develop to a size of 2.9–3.3 mm (0.11–0.13 in). Newly hatched larvae have a carapace length of 1.7–2.2 mm (0.067–0.087 in), and are present in smaller numbers than the eggs, with a maximum of 43 observed on a single female. This extended larval release has previously been found in other sub-Antarctic decapods, and is an adaptation to the low temperature, the long time taken for brooding, and the low overall fecundity.[8]

Edibility

The meat of T. birsteini is reported to be excellent,[7] and it is thought that the species could be commercially exploited if sufficient concentrations could be discovered.[4] The average weight of a caught individual is about 150 grams (5.3 oz), of which 30% (45 g or 1.6 oz) is the meaty tail. Daily yields of 19 kilograms (42 lb) are typical.[5]

References
  1. R. Wahle (2011). "Thymops birsteini". The IUCN Red List of Threatened Species. IUCN. 2011: e.T170038A6717105. doi:10.2305/IUCN.UK.2011-1.RLTS.T170038A6717105.en.
  2. "Thymops". Integrated Taxonomic Information System.
  3. "Thymops birsteini". Integrated Taxonomic Information System.
  4. Lipke Holthuis (1990). "Thymops birsteini". Marine Lobsters of the World. FAO.
  5. Arianna Masello. "Langosta oceánica" (in Spanish). Dirección Nacional de Recurcos Acuaticos.
  6. "Discover Life map of Thymops". GBIF Data Portal. Retrieved February 2, 2009.
  7. Enrique E. Boschi. "Thymops birsteini" (PDF). Atlas de Sensibilidad Ambiental de la Costa y el Mar Argentino. Secretaría de Ambiente y Desarrollo Sustentable.
  8. Vladimir Laptikhovsky & Pablo Reyes (2009). "Distribution and reproductive biology of a subantarctic deep-sea lobster, the Patagonian lobsterette Thymops birsteini (Zarenkov and Semenov, 1972) (Decapoda, Astacidea, Nephropidae)". Journal of Natural History. 43 (1–2): 35–46. doi:10.1080/00222930802567099. S2CID 84827982.
  9. G. M. Pilling; M. G. Purves; T. M. Daw; D. A. Agnew & J. C. Xavier (2001). "The stomach contents of Patagonian toothfish around South Georgia (South Atlantic)". Journal of Fish Biology. 59 (5): 1370–1384. doi:10.1006/jfbi.2001.1748. Archived from the original on 2013-01-05.
  10. Cynthia Yau; Martin A. Collins; Phil M. Bagley; Inigo Everson & Imants G. Priede (2002). "Scavenging by megabenthos and demersal fish on the South Georgia slope". Antarctic Science. 14 (1): 16–24. Bibcode:2002AntSc..14...16Y. doi:10.1017/S0954102002000536.
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