Diphasia robusta Fraser, 1943a

Calder, Dale R. & Choong, Henry H. C., 2018, Names of hydroids (Cnidaria, Hydrozoa) established by Charles McLean Fraser (1872 - 1946), excluding those from Allan Hancock Expeditions, Zootaxa 4487 (1), pp. 1-83: 44

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Diphasia robusta Fraser, 1943a


Diphasia robusta Fraser, 1943a 

Diphasia robusta Fraser, 1943a: 80  , pl. 19, figs. 11a, b [invalid junior primary homonym of Diphasia attenuata robusta Billard, 1924  ].

Type material. None known to exist.

Type locality. USA, Massachusetts: off George’s Bank, Canyon D ( Lydonia Canyon ), 40°23’N, 67°39’W, 640– 283 m ( Fraser 1943a).GoogleMaps 

Current status. Invalid.

Remarks. Although Fraser (1943a) described Diphasia robusta  from specimens in collections at the MCZAbout MCZ, no record of the species currently exists in the online database of that museum. A search for the hydroid in collections at MCZAbout MCZ during a visit by one of us ( DRC) in November 2017 was unsuccessful. No type material of it is recorded in online records of the RBCMAbout RBCM, AMNHAbout AMNH, NMNHAbout NMNH, CASAbout CAS, or YPMAbout YPM.

Specimens of Diphasia robusta  described by Fraser were collected in Lydonia Canyon, at the edge of the continental shelf off Nantucket Island, Massachusetts, on 24 July 1936 during a cruise of R/V Atlantis  . Except for the robust nature of its colony ( Fraser 1947a), the morphology of the species generally resembles that of D. fallax ( Johnston, 1847)  . Its female gonophores have yet to be described.

Although currently listed as valid in WoRMS, Diphasia robusta Fraser, 1943a  is a permanently invalid junior primary homonym of Diphasia attenuata robusta Billard, 1924  ( ICZN Art. 57.2). A new replacement name, D. alta  (derived from the Latin adjective altus and used in the meaning of “deep”, in reference to occurrence of this hydroid in bathyal waters), is proposed here for the species.


Museum of Comparative Zoology


Royal British Columbia Museum


American Museum of Natural History


Smithsonian Institution, National Museum of Natural History


California Academy of Sciences


Peabody Museum of Natural History


Diphasia robusta Fraser, 1943a

Calder, Dale R. & Choong, Henry H. C. 2018


Diphasia robusta

Fraser, 1943a : 80