. Bulletin. Natural history; Natural history. 452 Illinois Natural History Survey Bulletin Vol. 31, Art. 10 Table 6.—Relationship between size, age, and ovary weight of Lepomis symmetricus fe- males and the number of mature ova produced. An age of 1 year = 1 1 — 13 months, 2 years = 23-25 months. Data from TCWC 3643, UT , and INHS 17583, as well as that from Wolf Lake, are included. Standard Length in mm Adjusted Body Weight in Grams* Ovary Weight Number of Mature (orange or translucent, mm) Ova 34 326 34 219 36 491 3V 368 37 403
. Bulletin. Natural history; Natural history. 452 Illinois Natural History Survey Bulletin Vol. 31, Art. 10 Table 6.—Relationship between size, age, and ovary weight of Lepomis symmetricus fe- males and the number of mature ova produced. An age of 1 year = 1 1 — 13 months, 2 years = 23-25 months. Data from TCWC 3643, UT , and INHS 17583, as well as that from Wolf Lake, are included. Standard Length in mm Adjusted Body Weight in Grams* Ovary Weight Number of Mature (orange or translucent, mm) Ova 34 326 34 219 36 491 3V 368 37 403 38 330 39 432 40 417 42 421 43 374 45 364 45 378 51 2 ca 1600 52 2 cal400 ^Adjusted body weight is the specimen's weight after removal of the stomach, intestine, and liver. LOG Y=+ JULY SEPT, NOV. JAN. MAR. MAY Fig. 6—Monthly variations in ovarian weight relative to adjusted body weight of Lepomis symmetricus. The vertical axis is on a logarithmic scale. Ovaries from specimens collected June to April were from all age classes, but ovaries from specimens collected in May were from 2-year-old (24 months) fish. Spawning In Wolf Lake breeding individuals were captured as early as 24 April and as late as 30 May. Most spawning prob- ably occurred in May when water tem- peratures ranged from 18° to 22° C. Field observations and examination of museum specimens collected during all months of the year indicated that mid- April to early June was the typical spawning period for the species throughout its range (Table 7). Although spawning was not observed in the study area, ripe aquarium-held individuals collected 27 May 1975 en- gaged in prespawning activity for 7 days at water temperatures varying from 24° to 26° C. After presumed stimulation from a recent feeding the male began to court the female by nudging her with his snout along the posterior regions of her body and con- t
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