8,271 results
8,271 results for: Fish
- Animals
Secret Signal: Fish allurement that predators don’t see
In a rare demonstration of secret messaging in animals, a swordtail fish uses ultraviolet courtship signals that are invisible to a predator.
- Earth
Mapping watersheds invites comparisons
Computerized maps of environmental features for 154 of the largest river watersheds will soon be available to the public, free of charge.
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Putting Out the Welcome Mat: Chemical guides germ cells to gonads
A chemical made in the gonads attracts the embryonic cells that will one day form eggs or sperm.
- Animals
Fishy Paternity Defense: Bluegill dads: Not mine? Why bother?
Bluegill sunfish have provided an unusually tidy test of the much-discussed prediction that animal dads' diligence in child care depends on how certain they are that the offspring really are their own.
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Fig-Wasp Upset: Classic partnership isn’t so tidy after all
Genetic analysis suggests that a textbook example of a tight buddy system in nature—fig species that supposedly each have their own pollinating wasp species—may need to be rewritten.
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19426
Since the hypoxia described in this article isn’t caused directly by the fertilizer, but by the subsequent algae blooms, then perhaps an effective solution is to combat the algae. It might even be profitable to harvest the algae. If the fishing industry is capable of depleting the seas of species that we want there, then […]
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19557
This article reads as if there is something to be alarmed about. By selectively catching large fish, we have reduced “the mean size [of food fish to] one-fifth of what it was.” This is not cause for alarm. It is cause for a decision: What do we want, small fish or large fish? Humans are […]
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19719
To argue that the concentrations reported in this study are environmentally relevant is misleading. Those concentrations are usually in groundwater, not surface waters. I’ve been involved in the environmental field for almost 20 years and have yet to hear of any fish being caught in groundwater. John HarrisSacramento, Calif. Study coauthor Frank von Hippel notes […]
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19727
This article cites evidence of a severe genetic bottleneck, suggesting that perhaps no more than three pregnant females launched the expanding western Atlantic red lionfish population. How can there be “pregnant females” in an animal with the external fertilization described in the article? Do you mean a founder population of as few as three individuals? […]
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19758
It is not only the scientific literature that documents the unexpected “doughnut” pattern in swarms. Italo Calvino’s fictional Mr. Palomar observed (rather more lyrically) about the flocking of Roman starlings, “Finally a form emerges from the confused flutter of wings, advances, condenses: it is a circular shape, like a sphere, a bubble, the balloon-speech of […]
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19087
While reading that the cranial crest of the pterosaur Thalassodromeus helped regulate body temperature, I pondered another potential use. While gliding near the water, its crested head might act as a rudder for the large-wingspan animal. Perhaps the crest also included nerves that allowed Thalassodromeus to sense fleeing fish. Steve M. AdamsPlano, Texas Perhaps the […]
- Humans
Letters from the June 19, 2004, issue of Science News
Scan or scam? Using laser technology that has an apparent resolution of only about half a centimeter is somewhat laughable (“Laser scanners map rock art,” SN: 4/3/04, p. 222: Laser scanners map rock art). I also wondered whether the “fresh coat of desert varnish” was an April fool joke. Actually, I really look forward to […]
