Talk:Chondrichthyes

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The following was added by 200.1.19.70, which is in Chile: << There is a group on this subject in Chile more information on preyes@uach.cl >> Unclear how to access this. Is it an autoresponder? A mailing list? A finger address? The writer's personal box?

According to the National Audubon Society, Squaliformes can have either dorsal spines or an anal fin, but not both. This article says they can have dorsal spines, but never have anal fins. Tuf-Kat 09:25, Mar 4, 2004 (UTC)

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[edit] Poor grammar

It seems to me that the grammar used in this article is somewhat subpar and should be cleaned up. Perhaps the article should even be rewritten entirely. What does everyone think?

I've had a bash at tidying it. Nurg 02:57, 10 September 2006 (UTC)

[edit] Taxonomy

Is Chondrichthyes still considered an official class? Fishbase, the Catalogue of Life, the Global Biodiversity Information Facility, all recognize the split into Elasmobranchii(sharks and rays) and Holocephali(chimaeras). I was just wondering if this taxonomic grouping is still up for debate or if a general consensus has been reached.

[edit] The age of Chondrichthyes

This article needs to state at approximately what time period and years ago this class emerged. That is if there's any information. þ 10:59, 27 July 2007 (UTC)


[edit] Endothermic or no?

Chondrichthyes, section "Metabolism" says: "Chondrichthyes are ectothermic or cold blooded, meaning they do not have to warm themselves through eating. Therefore, metabolism is slow as well as the fact that Chondrichthyes members do not have to eat as much."

Fish, section "Homeothermy" says: "... certain species of fish maintain elevated body temperatures to varying degrees.... All sharks in the family Lamnidae – shortfin mako, long fin mako, white, porbeagle, and salmon shark – are known to have the capacity for endothermy, and evidence suggests the trait exists in family Alopiidae (thresher sharks).... porbeagle sharks ... maintain body temperatures elevated in excess of 20 °C above ambient water temperatures. See also gigantothermy. Endothermy, though metabolically costly, is thought to provide advantages such as increased contractile force of muscles, higher rates of central nervous system processing, and higher rates of digestion."

We need to reconcile these. -- Writtenonsand (talk) 20:37, 31 May 2008 (UTC)

  • The fast answer is that the fish article got it entirely correct, while Chondrichthyes didn't. So yes, some sharks, notably members of Lamnidae, are capable of raising their temperature above that of their surroundings. 212.10.87.199 (talk) 01:06, 7 June 2008 (UTC)