Pergamaster incertus Bell 1908

• Main Author: Mah, Christopher L.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2011
• Subjects: Biodiversity; Taxonomy; Animalia; Echinodermata; Asteroidea; Valvatida; Goniasteridae; Pergamaster; Pergamaster incertus; Ross Sea; Prydz Bay; Weddell
• Online Access: https://zenodo.org/record/6184365; https://doi.org/10.5281/zenodo.6184365

Pergamaster incertus (Bell, 1908) (Figures 14 A–F) Bell, 1908: 9; Fisher, 1940: 121; A.M. Clark, 1962: 22, 23; Bernasconi, 1963: 24 (as P. incertus) Fisher, 1940: 122; A.M. Clark, 1962: 22; Bernasconi, 1963: 24. (as P. synaptorus). Mein, 1992: 245 (as P. intercus) Synonymy of P. synaptorus Fisher, 1940. Character overlap between examined specimens suggests that P. synaptorus Fisher 1940 is a synonym of Pergamaster incertus (Bell, 1908). Fisher (1940) distinguished P. synaptorus from P. in c er t u s by only one character, the distalmost five to seven superomarginals abutted over the midline on the arm. One specimen (USNM E 13414) displayed the distalmost two to three superomarginals directly abutting, suggesting that this is a variable character. Character overlap between the two species is also present. Fisher (1940) described P. synaptorus has having 13–14 superomarginals on each arm (11–12 in the smaller paratype). Relatively large sized P. i n c e r t u s (USNM 1081793 w/R=4.0 cm) display 13–14 superomarginals on each arm. Geographic distribution and overall size of specimens do not show any clear distinction between the two species. Specimens with the “ P. synaptorus morphology” (i.e., with the abutted superomarginals) are indicated below to facilitate future studies. Comment on Prydz Bay specimens. Images of Pergamaster incertus provided by the Museum Victoria (T. Ohara, pers. comm., 2010) show intermediate morphology present on Prydz Bay specimens relative to the Weddell Quadrant (to the west) and Ross Quadrant (Ross Sea, to the east). Although specimens from Prydz Bay display characters such as bare actinal plates adjacent to adambulacrals and similarly shaped abactinal peripheral granules that place it within P. incertus, specimens from this locality also display characters more similar to P. triseriatus, such as the largely complete cover of actinal plates (other than those adjacent to the adambulacrals) with angular granules and relatively large abactinal peripheral granules and plates, suggesting ...