. Bulletin. Natural history; Natural history. 356 Illinois Natural History Survey Bulletin Vol. 33, Art. 4 19. Areola linear at midlength (Fig. 79); hooks on ischia of third pereiopods only (Fig. 9) Procambarus gracilis (p. 370) 19. Areola narrow but not linear (Fig. 80 & 81); hooks on ischia of third and fourth pereio- pods 20 20. Margins of rostrum elevated, converging to acumen (Fig. 80); narrow areola (Fig. 80) Procambarus acutus (p. 376) 20. Margins of rostrum not elevated; rostrum more rounded anteriorly (Fig. 81); wide areola (Fig. 81) Procambarus viaeviridis (p. 378) Fig. 79. Fig.
. Bulletin. Natural history; Natural history. 356 Illinois Natural History Survey Bulletin Vol. 33, Art. 4 19. Areola linear at midlength (Fig. 79); hooks on ischia of third pereiopods only (Fig. 9) Procambarus gracilis (p. 370) 19. Areola narrow but not linear (Fig. 80 & 81); hooks on ischia of third and fourth pereio- pods 20 20. Margins of rostrum elevated, converging to acumen (Fig. 80); narrow areola (Fig. 80) Procambarus acutus (p. 376) 20. Margins of rostrum not elevated; rostrum more rounded anteriorly (Fig. 81); wide areola (Fig. 81) Procambarus viaeviridis (p. 378) Fig. 79. Fig. 80. Fig. 81. SYSTEMATIC ACCOUNTS FAMILY PALAEMONIDAE Both shrimps native to Illinois are members of the family Palaemonidae, which is worldwide in distribution. Macrobrachium ohione, with 9-13 teeth along the upper edge of the ros- trum, is easily separable from Palae- monetes kadiakensis, which has only 6-8 (almost always 7) teeth. M. ohione, which reaches 100 mm in total length (tip of rostrum to tip of telson), also is much larger than P. kadiakensis, which reaches a maximum length of only about 50 mm. Genus Macrobrachium Bate Macrobrachium Bate 1868 Species of Macrobrachium, referred to as river shrimps, differ from species of Palaemonetes by possessing a hepatic spine, lacking a branchiostegal spine, and having the second pair of legs much longer than the first pair (in Palae- monetes the second pair is only slighth longer than the first pair). Although Macrobrachium contains aboiii 100 species worldwide (35 in the western hemisphere), only four (A/. ohione, M. acanthurus. M. carcinus, and M. oljersii) are found in the fresh- waters of the eastern United States (Hedgpeth 1949; Holthuis 1952). M. ohione is the only species of Macro- brachium found in the Mississippi River system. Macrobrachium ohione (Smith) (Fig. 82) Palaemon Ohionis Smith 1874 Palaemon sallei Kingsley 1882 Description.—Holthuis (1952) dis- tinguished M. ohione from other American species of Macrobrachiu
Size: 1156px × 2162px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
