Dawsonius Manning and Felder, 1991

Poore, Gary C. B., Dworschak, Peter C., Robles, Rafael, Mantelatto, Fernando L. & Felder, Darryl L., 2019, A new classification of Callianassidae and related families (Crustacea: Decapoda: Axiidea) derived from a molecular phylogeny with morphological support, Memoirs of Museum Victoria (Mem. Mus. Vic.) 78, pp. 73-146 : 119

publication ID

https://doi.org/ 10.24199/j.mmv.2019.78.05

publication LSID

urn:lsid:zoobank.org:pub:263C1363-0ADA-4972-9224-AC690A1FD238

DOI

https://doi.org/10.5281/zenodo.12214293

persistent identifier

https://treatment.plazi.org/id/038BBA5B-F270-0813-FF3D-B24CA8ABFAD6

treatment provided by

Felipe

scientific name

Dawsonius Manning and Felder, 1991
status

 

Dawsonius Manning and Felder, 1991

Dawsonius Manning and Felder, 1991: 785 .— Sakai, 2005b: 245.— Sakai, 2011: 508.

Gourretia .— Sakai, 2017a: 1128–1129 (partim).

Type species. Callianassa latispina Dawson, 1967 , by original designation and monotypy.

Diagnosis. Cardiac prominence present. Rostrum sharply triangular, produced to near apex of ocular lobes. Pleomere 6 with lateral projections. Male major cheliped merus with straight or weakly convex blade on lower margin bearing a short proximal curved spine and 1 or more distal spines; propodus rectangular, fingers fine, fixed finger smooth. Minor cheliped merus lower margin with erect proximal spine (as in major cheliped); propodus tapering, about 3 times as long as wide, with long narrow fingers. Pereopod 3 propodus triangular, with straight upper margin, expanded proximally on lower margin. Male pleopod 1 article 2 with lobed distomesial margin, distal notch, sharp curved distolateral apex. Telson parallel-sided over anterior half, then tapering to evenly rounded apex.

Remarks. Dawsonius latispina differs from other ctenochelids (except Paragourretia biffari Blanco Rambla and Liñero Arana, 1994 ) in having lateral projections on pleomere 6.

Manning and Felder (1991) differentiated Dawsonius from Gourretia on the absence of an exopod on maxilliped 3 and the sharp lateral projections on pleomere 6. We ( DLF) can confirm that maxillipedal 3 exopod is absent ( Dawson, 1967; Manning and Felder, 1991) and that Biffar’s (1971a) figure and Sakai’s (2011) observation of an exopod are in error. Biffar’s figures are a composite from types and Honduran material but the latter is P. biffari .

Sakai (2005b) treated the genus first as a synonym of Callianopsis and in an addendum as a separate genus that he differentiated from Callianopsis . Callianopsis is a member of another family. He did not explain what he meant by “sensu Sakai (not Manning and Felder, 1991)” before his new diagnosis. Sakai (2011) included Dawsonius in Gourretiidae . Sakai’s (2011) observations of a “ paratype ” and a “ lectotype ” ( USNM 103755, 172310) were not made on the holotype and paratype designated by Dawson (1967); these specimens may well have been misidentified. Sakai’s (2011: fig. 69E) figure of the apex of the male pleopod 2 is impossible to reconcile with Manning and Felder (1991: fig. 16i), which is typical of the family, nor with any ctenochelid.

Sakai (2017a) synonymised Dawsonius with Gourretia on the basis of the same male pleopods 1 and 2. In fact, Dawsonius is unique in pleopod 1 possessing a distomesial rounded blade and acute apex, whereas in Gourretia and Paragourretia the distomesial lobed is acute and smaller than the apical lobe.

DLF

Stetson University

USNM

Smithsonian Institution, National Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Callianassidae

Loc

Dawsonius Manning and Felder, 1991

Poore, Gary C. B., Dworschak, Peter C., Robles, Rafael, Mantelatto, Fernando L. & Felder, Darryl L. 2019
2019
Loc

Gourretia

Sakai, K. 2017: 1128
2017
Loc

Dawsonius

Sakai, K. 2011: 508
Sakai, K. 2005: 245
Manning, R. B. & Felder, D. L. 1991: 785
1991
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