“21. Eupagurus forceps (A.Milne-Edwards)
Cunningham, 1871:495 (Pagurus); A. Milne-Edwards, 1891:29 (E. comptus); Lagerberg. 1905:2, Figures 1-3 (E. comptus); Coutiere, 1906:9 (E. comptus); Doflein and Balss, 1912:31; Rathbun, 1910:598 (E. gayi); Porter, 1935:137 (Pagurus); Haig, 1955:19 (Pagurus).
Material. “Ob” station 451, 2 females, 12 females with eggs, 3 males; station 471, 11 males, 1 female with eggs; station 481, 2 males; station 482, 2 males.
The synonymy of this species results from the variation in the morphology of the right cheliped. Lagerberg (1905) clarified the confusion by showing that the development of the crest on the inner margin of the right chela and the profile of the carpus of the same limb are expressions of sexual dimorphism: in the male, the crest is higher than in the female and the carpus has a nearly triangular outline. Although Lagerberg's observations were later disregarded (Porter, 1935; Rathbun, 1910), Haig (1955) accepts this explanation in his comprehensive review and introduces further synonyms. My observations confirm Lagerberg's views of the variation of E. forceps.
This species was found at a temperature of 2.75-11.0°C near the Falkland Islands and in the Gulf of Ancud (Chile) (Haig, 1955; Brattstrom and Dahl, 1951). The only data on the temperature of egg development are those of Lagerberg and my own, and this ranges from 2.75 to 7.97°C. It appears that egg-bearing females found by Haig in the Strait of Magellan also live at a low, above-zero temperature. According to Lagerberg, egg development near. the Falkland Islands takes place in July, November and August. Eggs found in November contained fully developed larvae, while a female caught in September had 3 larvae. Haig encountered egg-bearing females in April and May in the Strait of Magellan and I found such females near Tierra del Fuego in June. Thus, larvae develop in April-November and hatch at the end of the year during summer and spring. Haig's largest female has a carapace length of 12.4mm; my egg-bearing specimens are somewhat smaller.
The eggs are oval, 1.0 X 0.95 mm. The number of eggs per batch increases with the carapace length. For Eupagurus forceps, the respective sizes are as follows.
Carapace length (mm) 2.7 3.9 4.3 4.4 4.9
Number of eggs . 44 189 246 234 276
This species lives on a variety of bottoms at a depth of 0-315m and is encountered on Macrocystis. Egg-bearing females are known from a depth of 2-25m (Lagerberg,1905); we have found them at a depth of 95-120m (station 451).
Distribution. A common species in waters of Patagonia and Tierra del Fuego (Cunningham, 1871; A. Milne- Edwards, 1891; Porter, 1903). Haig notes that this species, typical of the waters of the Strait of Magellan, is also found in the Peruvian province from Coquimbo on the Pacific side to the Falklands in the Atlantic. There is no confirmation of the findings near Cape Carrientes (Lagerberg, 1905) and East Patagonian Bank (Doflein and Balss,1912). Two stations (481 and 482) are from approximately the same area. Thus, the northern boundary of the range can be traced along 38°S. The only indication of the presence of this species in the Antarctic — at station 6 of the French Antarctic Expedition 1903-1905 — is unaccompanied by other details (Coutiêre,1906). Since the list of the stations of this expedition was not published, one can only assume that this station 6 is situated in Flandres Bay, 64°S, 17 February 1904 (Raillet and Henry,1907). Nevertheless, the presence of this species in the Antarctic requires confirmation.”
(Zarenkov, 1968)
Pagurus forceps is een tienpotigensoort uit de familie van de Paguridae.[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1836 door H. Milne Edwards.
Bronnen, noten en/of referenties
