Monterey Bay Aquarium Research Institute
Marine Botany

Chondracanthus exasperatus Taxonomy

One way to get a handle on the important characteristics and morphology of a species is to trace its taxonomic classification. C. exasperatus begins to show its true colors even in this straightforward exercise, as scientists have recently been struggling to place the alga in the appropriate Family, but we are getting ahead of our story....

Division: Rhodophyta

These are the red algae and they are definitely the largest group out there, as well as probably being the oldest eukaryotic algae. Basic characteristics include:

  • They lack flagellated cells;
  • Their major chlorophylls are a and d, with the phycobilins

  • phycoerythrin and phycocyanin as their accessory pigments;
  • Their storage product is floridean starch;
  • They have a morphological characteristic termed "pit plugs;"
  • And, their thylakoids occur singly in the chloroplast.


I want more information on C. exasperatus:
- Cell Structure and Chemistry
 - Pit Connections

Class: Rhodophyceae
This is now considered to be the only class in this division, however of the two subclasses which have recently been combined, Florideophycidae and Bangiophycidae, C. exasperatus is in the Florideophycidae.

Order: Gigarinaceae
This is a large and very heterogeneous group.   It is distinguished primarily by life history characteristics such as:

  • They are isomorphic or heteromorphic;
  • Their auxiliary cells are present before fertilization;
  • After fertilization, the diploid nucleus moves from the carpogonium

  • to the auxiliary cell via a connecting filament or ooblast;
  • And their tetraspores are cruciate or zonate (Lee, 1980).


I want more information on C. exasperatus:
 - Life History

Family: Chondracanthus
Chondracanthus on rockAnd here is where the real fun begins.   Up until recently, Chondracanthus exasperatus was known as Gigartina exasperata, and you may not have recognized it with its new name.   The family Chondracanthus was recently introduced as part of a larger effort to reclassify the Gigartinales.  

Some basic characteristics of this family include:

  • They have branched or foliose thalli, usually studded with "wart-like" projections, or papillae.
  • The gonimoblast filaments are surrounded by an outer enveloping cell.
  • The tetrasporangia form in the cortex, and the tetraspores are released through pores in the cell wall (Hommersand et al., 1993).*

*For more information about Chondracanthus life history characteristics, see C. exasperatus Life History

Genus/Species: Chondracanthus exasperatus
And finally, our beloved alga comes into its own.  And if you are interested in finding out more about this exasperating beauty, you are in the right place and have the rest of the web page to explore!

  [ C. exasperatus Home | Marine Botany Home ]
©1999 Devon Lake