228 Phylum Arthropoda 



References 



For the culture of cyclopids see also p. 230. 



For the culture of Cyclops see also p. 143. 

 Family Harpacticidae 



For the culture of Tigriopus julvus see p. 224. 

 Family Canthocamptidae 



For the culture of Canthocamptus see p. 143. 



For the culture of Copepoda see also p. 136. 



Order ostracoda 



SUGGESTIONS FOR CULTURING OSTRACODS 



Esther M. Patch and Lowell E. Noland, University of Wisconsin 



OSTRACODS are commonly found in nature at the bottom of pools, 

 lakes, or sluggish streams, where there is dead organic matter 

 which has passed the active fermentation stage of decay and is slowly 

 decomposing in a medium where oxygen is present at least in small 

 amounts. 



To rear ostracods in the laboratory it is desirable to duplicate natural 

 conditions as closely as possible, for instance by a hay-wheat infusion 

 made as follows: boil 2 grams of whole wheat grains and 3 grams of 

 timothy hay in enough water to cover them. Pond or lake water will 

 serve best since running water may carry pollutions, city water may con- 

 tain chemicals used in purification, and distilled water may have un- 

 desirable materials or lack desirable ones for optimum animal growth. 

 Boil the hay and wheat slowly for about 10 minutes and replace the 

 water with about a liter of that originally used, filtered or boiled so that 

 no Entomostraca will be present. Set aside for a few days until the 

 bacterial decomposition has passed from the acid to the alkaline stage, 

 when the ostracods may safely be placed in the medium. More of the 

 boiled wheat and hay and more of the boiled or filtered water may be 

 added from time to time as required. 



Cultures of these small Crustacea thrive well in a wide dish, covered 

 to retard evaporation but not so tightly as to exclude air. There are 

 species differences among ostracods in the requirements for light and 

 temperature as well as for food, but most of the common species do well 

 at ordinary room temperature and in sunlight which favors the growth 

 of algae. The above culture medium has been successful in rearing 

 ostracods to feed to very small salamander larvae. Thin slices of potato 

 (suggested by R. W. Sharpe in "Fresh Water Biology," edited by Ward 

 and Whipple) have also been used, as well as decayed lettuce. 



Ostracods may usually be gathered with a weighted net from the mud 

 or vegetation at the bottom of ponds and lakes ; at our laboratory they 



