Scales of variation in otolith elemental chemistry of juvenile staghorn sculpin (Leptocottus armatus) in three Pacific Northwest estuaries

2006 ◽  
Vol 151 (2) ◽  
pp. 483-494 ◽  
Author(s):  
J. A. Miller
2021 ◽  
Author(s):  
Hibiki Kimura ◽  
Tilo Pfalzgraff ◽  
Marie Levet ◽  
Yuuki Kawabata ◽  
John F Steffensen ◽  
...  

Fish perform rapid escape responses to avoid sudden predatory attacks. During escape responses, fish bend their bodies into a C-shape and quickly turn away from the predator and accelerate. The escape trajectory is determined by the initial turn (Stage 1) and a contralateral bend (Stage 2). Previous studies have used a single threat or model predator as a stimulus. In nature, however, multiple predators may attack from different directions simultaneously or in close succession. It is unknown whether fish are able to change the course of their escape response when startled by multiple stimuli at various time intervals. Pacific staghorn sculpin (Leptocottus armatus) were startled with a left and right visual stimulus in close succession. By varying the timing of the second stimulus, we were able to determine when and how a second stimulus could affect the escape response direction. Four treatments were used: a single visual stimulus (control); or two stimuli coming from opposite sides separated by a 0 ms (simultaneous treatment); a 33 ms; or a 83 ms time interval. The 33 ms and 83 ms time intervals were chosen to occur shortly before and after a predicted 60 ms visual escape latency (i.e. during Stage 1). The 0 ms and 33 ms treatments influenced both the escape trajectory and the Stage 1 turning angle, compared to a single stimulation, whereas the 83 ms treatment had no effect on the escape response. We conclude that Pacific staghorn sculpin can modulate their escape response only between stimulation and the onset of the response, but that escape responses are ballistic after the body motion has started.


1976 ◽  
Vol 54 (10) ◽  
pp. 1604-1609 ◽  
Author(s):  
William S. Marshall

Although hypophysectomy did not affect the number of skin mucous cells of sculpins in 5% seawater (1.4‰ salinity), there were fewer mucous cells in the gills, compared with intact and sham-operated controls. Injections of ovine prolactin (10 μg/g) maintained the number of gill mucous cells of the hypophysectomized fish at levels near that of sham-operated controls. The results are discussed in relation to the possible involvement of mucus secretion in teleost osmoregulation. An index method for easily estimating the number of mucous cells in the gill is described and evaluated.


1972 ◽  
Vol 29 (1) ◽  
pp. 107-108 ◽  
Author(s):  
Duane E. Phinney

In August 1967, a specimen of the Bering poacher, Occella dodacaedron (Tilesius), was taken by a commercial fisherman in Chignik Bay, Alaska; this catch indicates that it ranges farther south than Bristol Bay, the previously reported limit of its distribution. Sampling by beach seine by personnel of the Fisheries Research Institute in Chignik Lagoon, Alaska, in 1963–65 and in 1967, showed that the staghorn sculpin (Leptocottus armatus Girard) was a common resident; the northwestern range of the species is clarified.


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