Acoustic basis for fish prey discrimination by echolocating dolphins and porpoises

2009 ◽  
Vol 126 (1) ◽  
pp. 460-467 ◽  
Author(s):  
Whitlow W. L. Au ◽  
Brian K. Branstetter ◽  
Kelly J. Benoit-Bird ◽  
Ronald A. Kastelein
2011 ◽  
Author(s):  
Caroline M. DeLong ◽  
Irene Kannyo ◽  
Kelly J. Benoit-Bird ◽  
Whitlow W. L. Au
Keyword(s):  

1997 ◽  
Vol 9 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Masanori Takahashi ◽  
Tetsuo Iwami

The stomach contents of demersal fish in late January 1982 were analysed. Samples were taken at 100, 300 and 500 m depth south of Elephant Island, Bransfield Strait and north of Livingston Island, and at 800 m to the east of Smith Island. Fifty four taxa of fish belonging to 11 families were collected. The diets of 2101 fish representing 38 taxa were examined. These were classified into three categories, fish feeders, krill feeders and benthos feeders. Fish prey species fed on krill and/or benthos. Krill was a major dietary component for 32 (84.2%) out of 38 taxa. Gobionotothen gibberifrons was distributed at all 10 stations (100–800 m in depth) and its diet comprised krill and benthos. The present findings verify the importance of krill in the Antarctic marine ecosystem and indicate that krill is consumed by benthic fish at greater depths than previously reported.


2017 ◽  
Vol 284 (1852) ◽  
pp. 20170359 ◽  
Author(s):  
Arjun Nair ◽  
Christy Nguyen ◽  
Matthew J. McHenry

An escape response is a rapid manoeuvre used by prey to evade predators. Performing this manoeuvre at greater speed, in a favourable direction, or from a longer distance have been hypothesized to enhance the survival of prey, but these ideas are difficult to test experimentally. We examined how prey survival depends on escape kinematics through a novel combination of experimentation and mathematical modelling. This approach focused on zebrafish ( Danio rerio ) larvae under predation by adults and juveniles of the same species. High-speed three-dimensional kinematics were used to track the body position of prey and predator and to determine the probability of behavioural actions by both fish. These measurements provided the basis for an agent-based probabilistic model that simulated the trajectories of the animals. Predictions of survivorship by this model were found by Monte Carlo simulations to agree with our observations and we examined how these predictions varied by changing individual model parameters. Contrary to expectation, we found that survival may not be improved by increasing the speed or altering the direction of the escape. Rather, zebrafish larvae operate with sufficiently high locomotor performance due to the relatively slow approach and limited range of suction feeding by fish predators. We did find that survival was enhanced when prey responded from a greater distance. This is an ability that depends on the capacity of the visual and lateral line systems to detect a looming threat. Therefore, performance in sensing, and not locomotion, is decisive for improving the survival of larval fish prey. These results offer a framework for understanding the evolution of predator–prey strategy that may inform prey survival in a broad diversity of animals.


2002 ◽  
Vol 53 (1) ◽  
pp. 49 ◽  
Author(s):  
S. D. Goldsworthy ◽  
M. Lewis ◽  
R. Williams ◽  
X. He ◽  
J. W. Young ◽  
...  

A total of 1423 stomach samples were taken from Patagonian toothfish, Dissostichus eleginoides, caught by bottom trawls at two fishing grounds near Macquarie I., over three fishing seasons. Fish were caught at depths ranging from 500 to 1290 m, and ranged in size from 310 to 1490 mm total length. The 462 stomach samples (32%) that contained prey items indicated that toothfish preyed on a broad range of species including fish, cephalopods and crustaceans (58%, 32% and 10% biomass, respectively), suggesting that they are opportunistic predators. The bathypelagic fish Bathylagus sp. was the most important fish prey (14% dietary biomass); however, nototheniid, macrourid, morid and myctophid fish were also taken. The squid Gonatus antarcticus was also an important prey species (16% biomass), and many other cephalopod species were taken in low frequency. Prawnlike crustaceans (Nematocarcinidae, Mysididae, Sergestidae and Euphausiidae) were the most important crustaceans taken (9% of prey biomass). Significant inter-seasonal and inter-fishing-ground differences in diet were found, but dietary composition was not related to fishing depth, fish size (with the exception of one fishing ground in one season) or the time of day of capture. Comparison with other studies reveals biogeographical differences in the diet of toothfish.


2011 ◽  
Vol 68 (10) ◽  
pp. 1732-1743 ◽  
Author(s):  
Jodie Kemp ◽  
Stephen E. Swearer ◽  
Gregory P. Jenkins ◽  
Simon Robertson

Fine-scale shape variation and the added effect of partial digestion often limits accurate identification of different teleost prey species in marine diet studies using otoliths. We evaluated the use of fine-scale shape and trace element variation in digested otoliths to identify fish prey species from the diet of predators. Fourier analysis of otolith shape revealed significant variation between red cod ( Pseudophycis bachus ) and bearded rock cod ( Pseudophycis barbata ) otoliths. Incorporating otoliths that had been consumed by Australian fur seals ( Arctocephalus pusillus doriferus ) into a Fourier analysis discriminant model identified 73% of otoliths as those of red cod and 27% as those of bearded rock cod. However, in vitro digestion of red cod and bearded rock cod otoliths resulted in incorrect classification of both cod species otoliths to varying degrees when using Fourier analysis shape descriptors. There was significant variation between red cod and bearded rock cod otolith core chemistry. Incorporating otoliths consumed by the seals into an otolith core chemistry discriminant model identified all otoliths as those of red cod. Using otolith core chemistry to identify prey species was found to be successful, and there is great potential for this technique to have wider applications in investigating ecosystem trophic interactions.


2018 ◽  
Vol 600 ◽  
pp. 111-126 ◽  
Author(s):  
KB Huebert ◽  
J Pätsch ◽  
M Hufnagl ◽  
M Kreus ◽  
MA Peck

2012 ◽  
Vol 18 (2) ◽  
pp. 57 ◽  
Author(s):  
Bram Setyadji ◽  
Andi Bahtiar ◽  
Dian Novianto

Feeding habit of tuna in Indian Ocean has been described around Sri Lanka, Indian Waters, Andaman Sea, western Indian Ocean (<em>Seychelles Islands</em>), western equatorial Indian Ocean whereas the tunas feeding habit study in Eastern Indian Oceanis merely in existence. The purpose of this study is to investigate the stomach content of three tuna species (bigeye tuna, yellowfin tuna, and skipjack tuna), apex predator in the southern part of Eastern Indian Ocean. The study was conducted in March – April, 2010 on the basis of catches of commercial tuna longline vessel based in Port of Benoa. A total of 53 individual fishes were collected, consisting of bigeye tuna (<em>Thunnus obesus</em>), yellowfin tuna (<em>Thunnus albacores</em>), and skipjack tuna (<em>Katsuwonus</em> <em>pelamis</em>). Stomach specimens were collected and analyzed.Analysis was conducted on the basis of index of preponderance method. The diet of the three tuna species showed fishes as the main diet (56–82%), followed by cephalopods (squids) as the complementary diet (0–8%), and crustaceans (shrimps) as the additional diet (2–4%). Fish prey composed of 6 families i.e. Alepisauridae, Bramidae, Carangidae, Clupeidae, Engraulidae, and Scombridae.


2002 ◽  
Vol 80 (12) ◽  
pp. 2190-2199 ◽  
Author(s):  
D F Bertram ◽  
T Golumbia ◽  
G K Davoren ◽  
A Harfenist ◽  
J Brown

To investigate the utility of short visits to seabird colonies to gauge nestling growth performance and diet, in 4 consecutive years (1995–1998) we measured nestling development and diet of Rhinoceros Auklets (Cerorhinca monocerata) at three colonies in British Columbia: Seabird Rocks, Triangle Island, and SGaang Gwaii (Anthony Island). In all years, nestlings of a given wing length on Triangle Island were significantly smaller than those on Seabird Rocks or SGaang Gwaii. Meals were also significantly lighter on Triangle Island than on Seabird Rocks or SGaang Gwaii; meals on the latter two islands were indistinguishable in mass. Retarded nestling development and small meal size on Triangle Island likely reflect the large contribution of rockfish (Sebastes spp.) to nestling diet on that colony alone. The intercolony differences in nestling performance appear to reflect the strong influence of local fish prey populations. Nonetheless, a united decline in performance in 1996 and subsequent increase on all colonies suggest the influence of large-scale ocean climate phenomena on our entire study region and beyond. We did not, however, observe noticeable effects of the 1997–1998 El Niño Southern Oscillation event on nestling growth performance or diet. We discuss the utility of our short-visit techniques for seabird-monitoring programs.


2004 ◽  
Vol 61 (11) ◽  
pp. 2135-2143 ◽  
Author(s):  
Nathan J Dorn ◽  
Gary G Mittelbach

While crayfish are traditionally considered fish prey, they are capable of feeding on substrate-bound fish eggs and their introductions have been blamed for the decline in fish populations in Europe and North America. To investigate their potential effects on fish reproductive success we measured the effects of a native crayfish (Orconectes virilis) on the reproductive success of two substrate-nesting sunfish, pumpkinseed (Lepomis gibbosus) and bluegill (Lepomis macrochirus), in replicated pond experiments. Crayfish were observed feeding on eggs in both experiments. Crayfish presence delayed successful reproduction by pumpkinseeds in densely vegetated ponds, resulting in lower young-of-the-year biomass in ponds with crayfish. In the second experiment, with bluegills in less-vegetated ponds, crayfish prevented successful reproduction entirely. However, when we added crayfish-proof exclosures to the crayfish ponds late in the summer, bluegills located the crayfish-free habitat and successfully reproduced inside the exclosures (1 month after first successful reproduction in control ponds). The results of these experiments demonstrate the potential strong negative effects of crayfish on sunfish reproduction and suggest that the spatial distribution of crayfish and other egg predators may influence fish nesting behaviors and habitat choices. Further studies are needed to determine the magnitude of crayfish effects in natural lakes and ponds where sunfish and crayfish co-occur.


Sign in / Sign up

Export Citation Format

Share Document