Chapter 9 

 Order 2 Cryptomonadina Stein 



THE cryptomonads differ from the chrysomonads in having a 

 constant body form. Pseudopodia are very rarely formed, as 

 the body is covered by a pellicle. The majority show dorso-ventral 

 differentiation, with an oblique longitudinal furrow. 1-2 unequal 

 flagella arise from the furrow or from the cytopharynx. In case 2 

 flagella are present, both may be directed anteriorly or one poster- 

 iorly. These organisms are free-swimming or creeping. 



One or two chromatophores are usually present. They are discoid 

 or band-form. The color of chromatophores varies: yellow, brown, 

 red, olive-green; the nature of the pigment is not well understood, 

 but it is said to be similar to that which is found in the Dinoflagel- 

 lata (Pascher). One or more spherical pyrenoids which are enclosed 

 within a starch envelope appear to occur outside the chromato- 

 phores. Nutrition is mostly holophytic; a few are saprozoic or holo- 

 zoic. Assimilation products are solid discoid carbohydrates which 

 stain blue with iodine in Cryptomonas or which stain reddish violet 

 by iodine in Cryptochrysis ; fat and starch are produced in holo- 

 zoic forms which feed upon bacteria and small Protozoa. The stigma 

 is usually located near the insertion point of the flagella. Con- 

 tractile vacuoles, one to several, are simple and are situated near the 

 cytopharynx. A single vesicular nucleus is ordinarily located near 

 the middle of the body. 



Asexual reproduction, by longitudinal fission, takes place in 

 either the active or the non-motile stage. Sexual reproduction is un- 

 known. Some cryptomonads form palmella stage and others gelati- 

 nous aggregates. In the suborder Phaeocapsina, the palmella stage is 

 permanent. Cysts are spherical, and the cyst wall is composed of 

 cellulose. The Cryptomonadina occur in fresh or sea water, living 

 also often as symbionts in marine organisms. 



Flagellate forms predominant Suborder 1 Eucryptomonadina 



Palmella stage permanent Suborder 2 Phaeocapsina (p. 275) 



Suborder 1 Eucryptomonadina Pascher 



Truncate anteriorly; 2 anterior flagella; with an oblique furrow near 

 anterior end Family 1 Cryptomonadidae (p. 273) 



Reniform; with 2 lateral flagella; furrow equatorial 



Family 2 Nephroselmidae (p. 274) 



272 



