Rhodophyta, Red Algae
Ceramium Roth 1797
Rhodophyta, Order: Ceramiales; Family: Ceramiaceae.
Etymology
The genus name derives from Greek for ‘small tube’ or ‘vase’.
Description
The Ceramium resembles a bush made of filaments. Microscopic examination reveals an elongated, multi-jointed thallus. The joints are thick and comprise a ring of smaller cells. The reproductive organs are dark and hidden inside the joints. The branching is dichotomous, and at the end of each branch, a pair of bent, pincer-like branches face each other.
Size
A tiny alga, its branches grow only a few centimeters in length.
Colour
The algal is mostly transparent. Hints of red tending towards brown appear in the joints.
Special features
The Ceramium resembles the Centroceras clavulatum, and the two are easily confused. However, the Ceramium is rarer, thicker, softer when touched and lighter.
Habitat
The alga grows upon rocks and as an epiphyte upon other plants. It is usually found on the sea-facing edges of the abrasion platform and on rocks in the water.
Biology and reproduction
The Ceramium has a three-stage life cycle. It is a favourite dish for algae-eating fish and other herbivores, and this is probably the reason for its scarcity in areas exposed to fish.
Seasonality and distribution
The genus is quite common in most seas. In Israel, it can be found year-round, although a rise in population is seen in the warmer months.
Additional species
The genus includes dozens of species found worldwide. In this region, about 16 species have so far been identified. A partial list of these includes species classified in the Mediterranean on different occasions:
Ceramium bertholdii Funk
Ceramium ciliatum (Ellis) Ducluzeau
Ceramium cimbricum H. Petersen
Ceramium circinatum K.tzing
Ceramium codii (Richards) G. Feldmann-Mazoyer
Ceramium comptum B.rgesen
Ceramium deslongchampii Chauvin and Duby
Ceramium diaphanum (Lightfoot) Roth
Ceramium echionotum J. Agardh
Ceramium fastigiatum Harvey
Ceramium flaccidum (Harvey and K.tzing) Ardissone
Ceramium gracillimum (K.tzing) Griffiths and Harvey
Ceramium nodulosum (Lightfoot) Ducluzeau
Ceramium rubrum (Hudson) C. Agardh
Ceramium strictum Gr.ville and Harvey
Ceramium - micrscopic structure of
Ceramium tenuissimum (Roth) Areschough. the thallus.
Ceramium - a condensed, bracelet-like joint
Ceramium species have been used along Pacific shores to cure lung diseases and for the manufacture of cosmetics. One species, Ceramium rubrum, possibly present in the Eastern Mediterranean, contains antibiotic substances that arrest the growth of bacteria.