. Culture methods for invertebrate animals;. Invertebrates -- Cultures and culture media; Invertebrates -- Collection and preservation. Odonata 269. Fig. 62.—"Boat" for rearing nymphs of Ischnura verticalis. (About natural size.) 144 threads to the inch, which is fine enough to retain the smallest nymph and its food organisms, and yet permits circulation of water. The silk was fastened to the frame with paraffin, and the frame was covered with a film of paraffin to reduce "; The little "sail" was a paper tag, attached by a special pin, and was used t
. Culture methods for invertebrate animals;. Invertebrates -- Cultures and culture media; Invertebrates -- Collection and preservation. Odonata 269. Fig. 62.—"Boat" for rearing nymphs of Ischnura verticalis. (About natural size.) 144 threads to the inch, which is fine enough to retain the smallest nymph and its food organisms, and yet permits circulation of water. The silk was fastened to the frame with paraffin, and the frame was covered with a film of paraffin to reduce "; The little "sail" was a paper tag, attached by a special pin, and was used to record dates of molting and other data. The advantage of such containers, over Syracuse watch glasses for instance, is that the nymph has all the benefits of a large vessel of water, which does not stagnate so quickly, and is less subject to tem- perature fluctuations. When the nymphs were nearly full grown (, in the last two or three instars) and were inclined to crawl out of the boats, they were transferred to glass tumblers, provided with a strip of wire screen to serve as a perch. Previous to transformation, the glasses were covered with cheesecloth fastened down with an elastic band, thus making con- venient emergence chambers in which to observe molting. The young imagos were then transferred to individual aquarium-cages, similar to, but smaller than, the stock cages (Fig. 61), one pair to a cage, so that data might be kept on mating, oviposition, color changes, etc. Feeding. Both nymphs and adults are strictly carnivorous, and for any large scale rearing it is necessary to maintain colonies of food organisms. The adults have a preference for dipterous insect prey. One method of supply was to stock the breeding tank with quantities of full grown blood worms and mosquito larvae and pupae, and to allow the damsel- flies to feed on the emerging midges and mosquitos. Later in the season when this supply failed it was necessary to collect midges in the woods with a net
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Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
