Chapter 8 

 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 pelhcle. 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 posteriorly. These organisms are free-swimming or creeping. 

 1-2 chromatophores are usually present. They are discoid or 

 band-form. The color of chromatophores vary from common 

 brown, red, olive-green up to blue-green. The nature of the pig- 

 ment is not well understood, but it is said to be similar to that 

 which is found in the Dinofiagellata (Pascher). One or more 

 spherical pyrenoids which are enclosed within a starch envelope 

 appear to occur outside the chromatophores. Nutrition is mostly 

 holophytic; a few saprozoic or holozoic. Assimilation products are 

 solid discoid carbohydrates which stain blue with iodine in 

 Cryptomonas or which stain reddish violet by iodine as in Crypto- 

 chrysis; fat and starch are produced in holozoic forms which feed 

 upon bacteria and small Protozoa. The stigma is usually as- 

 sociated with the insertion point of the flagella. Contractile 

 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 

 unknown. Some cryptomonads form palmella stage and others 

 gelatinous aggregates. In the suborder Phaeocapsina, the pal- 

 mella 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 (p. 185) 



Palmella stage permanent Suborder 2 Phaeocapsina (p. 187) 



184 



