Ceramium riosmenae sp. nov. (Ceramiaceae, Rhodophyta): a new complete corticated species on Gracilaria from Baja California Sur, Mexico

doi:2011.26.4.289

Algae > Volume 26(4); 2011 > Article

Algae 2011;26(4): 289-297. doi: https://doi.org/10.4490/algae.2011.26.4.289

Boo Yeon Won and Tae Oh Cho

*Corresponding Author

Email: tocho@chosun.ac.kr

ABSTRACT

Ceramium riosmenae sp. nov. is described from Baja California Sur, Mexico based on morphological and molecular data. The new species is characterized by erect thalli only, penetrating rhizoids on Gracilaria, 7-8 periaxial cells, five cortical initials per periaxial cell, complete cortication throughout, an average of 11-12 segments between branching points, rare adventitious branchlets, and cruciate tetrasporangia. Although C. riosmenae sp. nov. is similar to C. interruptum, C. sinicola, and C. codicola reported from Baja California Sur, Mexico in size and habit, it differs from these species in the number of cortical initials, habit, degree of cortication, host, and the shape of rhizoidal tips. C. riosmenae is separated from C. interruptum with interrupted cortication and four cortical initials from C. sinicola with spins near the apex and incomplete cortication near the base and from C. codicola with bulbous rhizoids on Codium. Our rbcL sequences reveal sufficient sequence divergence (2.4-3.9%) between C. riosmenae and C. interruptum, C. sinicola, and C. codicola to warrant species recognition and to separate C. riosmenae from these species on a phylogenetic tree.

Key words: Ceramium riosmenae sp. nov. Ceramiaceae; morphology; phylogeny; rbcL; Rhodophyta; taxonomy