Daily Rings in Otoliths of Three Species of Lepomis and Tilapia mossambica

1977 ◽  
Vol 34 (3) ◽  
pp. 332-340 ◽  
Author(s):  
Bruce D. Taubert ◽  
Daniel W. Coble

Daily rings formed on otoliths of known-age, laboratory-raised pumpkinseed (Lepomis gibbosus), green sunflsh (L. cyanellus), bluegill (L. macrochirus), and mozambique mouthbrooder (Tilapia mossambica) for at least 176, 170, 125, and 60 days, respectively. Subdaily rings found in young laboratory and wild fish were easily distinguished from daily rings. Width of daily rings on otoliths of green sunfish was linearly related to daily increase in length of fish, but the number of rings was a product of age of fish only, not length of fish or otolith radius. Growth and daily ring formation on otoliths in wild bluegill and largemouth bass (Micropterus salmoides) appeared to be similar to those in laboratory-raised fish. Otoliths of green sunfish held under simulated winter conditions ceased to produce daily rings, but did form an annulus. Two kinds of otolith tissue were present in most of the larger laboratory fish and wild bluegill but were not observed in wild largemouth bass. The first type, present in all areas of the otolith except the extreme posterior end, was translucent and had well-defined daily rings. The second type, present only in the posterior end, was opaque and had poorly etched daily rings that were difficult to discern. Both tissues were calcium carbonate in the aragonite form. Daily rings were found on otoliths offish held at constant temperature. Results of experiments with young mouthbrooders held under various light–dark and feeding cycles suggested that a 24-h light–dark cycle that entrained an internal, diurnal clock was required for daily ring production.

1980 ◽  
Vol 37 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Michael L. Toneys ◽  
Daniel W. Coble

In laboratory experiments young-of-the-year green sunfish, Lepomis cyanellus, largemouth bass, Micropterus salmoides, brook trout, Salvelinus fontinalis, and yellow perch, Perca flavescens, were held for 4 mo under simulated winter conditions (2–4 °C; photoperiod of 9 h light: 15 h dark) in solutions of various osmotic strengths, from 90% distilled water to 1.0% NaCl. Mortality in three of five experiments often was greater in salt solutions, indicating that NaCl did not increase survival. Survival was greater for larger yellow perch than smaller but was not related to size in the other species. Hematocrit was depressed below control levels in all solutions at the end of experiments. The fish generally were able to regulate plasma osmotic concentration in all solutions except the highest NaCl concentrations, where plasma osmolality was often significantly higher than in the control at the end of experiments. Plasma Na+ and Cl− typically decreased and then recovered at low temperatures. Presence of Na+ and Cl− in the external medium tended to alleviate their loss from plasma. Changes in plasma Na+ and Cl− were not related to mortality in hypoionic solutions but usually did correspond to changes in plasma osmolality. Fat content of survivors declined and water content increased for all species, but the losses and gains were not related to osmolality of solutions. Low fat content probably was not a cause of death.Key words: Mortality, electrolyte regulation, osmolality, hematocrit, fat depletion, winter conditions, green sunfish, largemouth bass, brook trout, yellow perch, sodium, chloride


2008 ◽  
Vol 42 (2008) ◽  
pp. 7-10
Author(s):  
Scott C. Williams

Escape of predatory fish from impoundments and their impact on native stream fishes, especially threatened and endangered fish, are concerns of fishery managers. This investigation was designed to identify if fish, especially predatory fish, would escape from an impoundment with a surface withdrawal spillway pipe, and enter a stream. From March 16, 2005 through June 2, 2006, all discharge from the impoundment was forced to flow through a steel cage constructed of one-half inch steel mesh, which trapped escaping fish consisting of 37 largemouth bass Micropterus salmoides, 141 bluegill Lepomis macrochirus, and 197 green sunfish Lepomis cyanellus. The average sizes of largemouth bass, bluegill and green sunfish caught were 3.9 inches (range 2.5 to 10.5 inches), 1.4 inches (range 0.75 to 2.5 inches), and 2.2 inches (range 1.3 to 3.3 inches), respectively. Most of the fish escapement occurred during the months of April, May, and September when discharge was highest. Thus fish can readily escape through a surface withdrawal spillway pipe during periods of discharge.


2013 ◽  
Vol 18 (3) ◽  
pp. 654-659 ◽  
Author(s):  
Dongmei MA ◽  
Guocheng DEND ◽  
Junjie BAI ◽  
Shengjie LI ◽  
Xiaoyan JIANG ◽  
...  

2018 ◽  
Author(s):  
Bryan C. Chakoumakos ◽  
◽  
Brenda M. Pracheil ◽  
R. Seth Wood ◽  
Alison Loeppky ◽  
...  

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