. Fresh-water biology. Freshwater biology. 786 FRESH-WATER BIOLOGY 8 (i) Head fused with first thoracic segment, but fusion indicated by distinct indentations on lateral margins; carapace half en- tire length and violin-shaped 9 9 (id) Second antennae as long as carapace. Ergasilus versicolor Wilson 19ii. Found upon species of Fig. 1240. Ergasilus versicolor. (After Wilson.) 10 (9) Second antennae only one-half length of carapace. Ergasilus chautauquaensis Fellows 1887. Suborder Branchiura There is but one family in this suborder, — the Arguhdae. They are ectoparasites upon fish, and
. Fresh-water biology. Freshwater biology. 786 FRESH-WATER BIOLOGY 8 (i) Head fused with first thoracic segment, but fusion indicated by distinct indentations on lateral margins; carapace half en- tire length and violin-shaped 9 9 (id) Second antennae as long as carapace. Ergasilus versicolor Wilson 19ii. Found upon species of Fig. 1240. Ergasilus versicolor. (After Wilson.) 10 (9) Second antennae only one-half length of carapace. Ergasilus chautauquaensis Fellows 1887. Suborder Branchiura There is but one family in this suborder, — the Arguhdae. They are ectoparasites upon fish, and are commonly known as fish Kce. They have compound eyes, four or five pairs of swimming feet, and the first maxillipedes are modified into a pair of sucking disks. In connection with the mouth is a true stinging organ which pene- trates the skin of the host. They are found most abundantly in the branchial chamber of the host, but may attach themselves to other parts of the body. It is a matter of interest in this connec- tion, as has been noted by Wilson, that they attach themselves in such a way as to place the long axis of the body parallel to that of the host, so that they will be less likely to be brushed off in its move- ments. To this end, too, the under side of the body of the Argulus is armed with backward-pointing spines, which aid in keeping it in place. Argulus is strictly dependent on the blood of its host for food, but can and does frequently swim about freely. Inas- much as the eggs are laid attached to stones and similar objects, it must leave the host at the breeding season. They are not con-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
