Calpasoma dactylopterum Fuhrmann, 1939

Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, Zootaxa 2590 (1), pp. 1-91 : 75

Calpasoma dactylopterum Fuhrmann, 1939

Fig. 49

Calpasoma dactyloptera Fuhrmann, 1939: 363 , figs. 3–6.– Matthews, 1966: 256.

Type locality. Switzerland: Neuchâtel, alongside Craspedacusta sowerbii in aquaria at the university ( Fuhrmann 1939) .

Material examined. None.

Description. (After Jankowski 2001): “Polyp…0.1–0.4 mm long; transparent to whitish; 8–32 (to 54) tentacles, 68–234 µm long and 8–15 µm wide; each tentacle contains 5–20 non grouped nematocyts (sic) (0.14 µm).”

Remarks. Matthews (1966), working in Hawaii, reported Calpasoma dactylopterum Fuhrmann, 1939 on the aquatic tracheophyte Elodea canadensis , purchased from an unstated source. Specimens of this freshwater cnidarian were not represented in collections at the Bishop Museum, and it was not observed during this study.

The cnidome of Calpasoma dactylopterum comprises heterotrichous microbasic euryteles, and reproduction occurs by formation of frustules ( Rahat & Campbell 1974).

There is disageement at present whether this is simply a form of Craspedacusta sowerbii Lankester, 1880 .

Reported distribution. Hawaii. Oahu: Honolulu, in aquaria on Elodea canadensis ( Matthews 1966) .

Worldwide. Holarctic, shallow fresh waters ( Jankowski et al. 2008).