Cryptomonad

Jump to navigation Jump to search
Cryptomonads
Rhodomonas salina
Rhodomonas salina
Scientific classification
Domain: Eukaryota
Kingdom: Chromalveolata
Phylum: Cryptophyta
Class: Cryptophyceae
Typical genera

Order Cryptomonadales    Campylomonas
   Chilomonas
   Chroomonas
   Cryptomonas
   Falcomonas
   Geminigera
   Guillardia
   Hemiselmis
   Plagioselmis
   Proteomonas
   Storeatula
   Rhodomonas
   Teleaulax
Order Goniomonadales
   Goniomonas

WikiDoc Resources for Cryptomonad

Articles

Most recent articles on Cryptomonad

Most cited articles on Cryptomonad

Review articles on Cryptomonad

Articles on Cryptomonad in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Cryptomonad

Images of Cryptomonad

Photos of Cryptomonad

Podcasts & MP3s on Cryptomonad

Videos on Cryptomonad

Evidence Based Medicine

Cochrane Collaboration on Cryptomonad

Bandolier on Cryptomonad

TRIP on Cryptomonad

Clinical Trials

Ongoing Trials on Cryptomonad at Clinical Trials.gov

Trial results on Cryptomonad

Clinical Trials on Cryptomonad at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Cryptomonad

NICE Guidance on Cryptomonad

NHS PRODIGY Guidance

FDA on Cryptomonad

CDC on Cryptomonad

Books

Books on Cryptomonad

News

Cryptomonad in the news

Be alerted to news on Cryptomonad

News trends on Cryptomonad

Commentary

Blogs on Cryptomonad

Definitions

Definitions of Cryptomonad

Patient Resources / Community

Patient resources on Cryptomonad

Discussion groups on Cryptomonad

Patient Handouts on Cryptomonad

Directions to Hospitals Treating Cryptomonad

Risk calculators and risk factors for Cryptomonad

Healthcare Provider Resources

Symptoms of Cryptomonad

Causes & Risk Factors for Cryptomonad

Diagnostic studies for Cryptomonad

Treatment of Cryptomonad

Continuing Medical Education (CME)

CME Programs on Cryptomonad

International

Cryptomonad en Espanol

Cryptomonad en Francais

Business

Cryptomonad in the Marketplace

Patents on Cryptomonad

Experimental / Informatics

List of terms related to Cryptomonad

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]


Overview

The cryptomonads are a small group of flagellates, most of which have chloroplasts. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10-50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella.

Cryptomonads distinguished by the presence of characteristic extrusomes called ejectisomes, which consist of two connected spiral ribbons held under tension. If the cells are irritated either by mechanical, chemical or light stress, they discharge, propelling the cell in a zig-zag course away from the disturbance. Large ejectisomes, visible under the light microscope, are associated with the pocket; smaller ones occur elsewhere on the cell.

Cryptomonads have one or two chloroplasts, except for Chilomonas which has leucoplasts and Goniomonas which lacks plastids entirely. These contain chlorophylls a and c, together with phycobiliproteins and other pigments, and vary in color from brown to green. Each is surrounded by four membranes, and there is a reduced cell nucleus called a nucleomorph between the middle two. This indicates that the chloroplast was derived from a eukaryotic symbiont, shown by genetic studies to have been a red alga.

A few cryptomonads, such as Cryptomonas, can form palmelloid stages, but readily escape the surrounding mucus to become free-living flagellates again. Cryptomonad flagella are inserted parallel to one another, and are covered by bipartite hairs called mastigonemes, formed within the endoplasmic reticulum and transported to the cell surface. Small scales may also be present on the flagella and cell body. The mitochondria have flate cristae, and mitosis is open; sexual reproduction has also been reported.

Originally the cryptomonads were considered close relatives of the dinoflagellates because of their similar pigmentation. Later botanists treated them as a separate division, Cryptophyta, while zoologists treated them as the flagellate order Cryptomonadida. There is considerable evidence that cryptomonad chloroplasts are closely related to those of the heterokonts and haptophytes, and the three groups are sometimes united as the Chromista. However, the case that the organisms themselves are closely related is not very strong, and they may have acquired chloroplasts independently.


Template:WH Template:WS