Talk:Channichthyidae

Wiki Education Foundation-supported course assignment
This article was the subject of a Wiki Education Foundation-supported course assignment, between 24 August 2020 and 5 December 2020. Further details are available on the course page. Student editor(s): Kiesol Stockholm. Peer reviewers: Ccoult2, Beemaxilla.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 18:51, 17 January 2022 (UTC)

Wiki Education Foundation-supported course assignment
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Ambiederman. Peer reviewers: Ambiederman.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 17:11, 16 January 2022 (UTC)

Name
Actually "icefish" is also used of two species in Salangidae, which is one of the reasons this article was at "crocodile icefish". It would be a better organization to have this name be a disambigger to the two different families, and would avoid the scorn of professional ichthyologists who might happen to visit. :-) Stan 17:37, 13 Aug 2004 (UTC)


 * Ok, but a disamb should point to at least two article, i.e. we also need an article on these Salangidae species. What are these? Also fish in the Antarctic Sea? Anyway, I deleted the crocodile from the icefish, as I made some Google searches and found that nobody except fishbase calls the crocodile icefish. But, please, go ahead, write a stub on Salangidae, and make a disambiguation page. Then everything should be correct. Simon A. 17:21, 14 Aug 2004 (UTC)


 * Just did a cheap-style disambig myself. You want to write about noddlefishes, which is the other name for these other icefishes? They seem to be found in rivers flowing from mainland Asia into the Pacific. Simon A. 17:51, 14 Aug 2004 (UTC)


 * I have to agree with Stan (I'm not a professional, but I care about accuracy just the same). Crocodile icefish is the accepted common name for this family, and therefore the article should be moved back there. The Southeast Asian Salangidae are known as both icefish and noodlefish, named after their transparency and poor ossification. As for a disambig page requiring more than two articles, that's not true; look what I did at hatchetfish. One article written is enough; someone looking for the other family can see that it needs to be written, and may do so. (I'll write it up myself eventually, if nobody beats me to it.)


 * Also, please note that the image you've uploaded (Image:Icefish-large.jpg) can't really be used on Wikipedia. The GFDL allows for commercial reproduction, and images under Crown copyright don't allow this: "Material on this website must not be used in a commercial context unless the written permission of the Ministry of Fisheries has been obtained." See Village pump for a discussion on this. -- Hadal 18:08, 14 Aug 2004 (UTC)


 * Hadal & Stan: Thanks for your comments. As I'm travelling the next two weeks, I might not be able to finish this stuff, so I suggest, you take over and do the changes as you see fit. Thanks. Simon A. 12:16, 17 Aug 2004 (UTC)

size?
There is no indication of scale in the image or the article. I can't tell if this fish is a centimeter long or a 10 meters long. Vicarious 06:03, 14 January 2006 (UTC)

On the image larva is shown - larva is less than 1 cm. But the data about size is totally wrong. Icefishes can reach usually 30 cm in length, maximum 70cm, not 5 - 10 m at any circumstances. Here is the review: http://link.springer.com/article/10.1007%2Fs00300-005-0019-z#/page-1 Figure 2 is the proof. — Preceding unsigned comment added by 194.85.26.61 (talk) 12:48, 28 October 2015 (UTC)

Inconsistent
Article states the blood contains less than 10% hemoglobin and then later it says it contains none at all. JMcC (talk) 23:38, 23 November 2010 (UTC)

Agreed; the article is not self-consistent. If the genese don't code for Hg I'd assume that means there is none. Or perhaps Hg is only found in 10% of the species? What is meant by describing the red blood cells as 'defunct'? Are they present but have no purpose? Wish I knew the answers, regrettably only have the questions! Rob Burbidge (talk) 13:19, 31 January 2011 (UTC)

A year later and this is still inconsistent, but I too lack the knowledge to correct it. Perhaps in the next year someone will. Zombiejesus (talk) 21:37, 24 December 2011 (UTC)

Image
I don't think this is the best image for this article. First, it's a photo of a larvae, not an adult, and the species isn't identified (Does anyone know what species this is? I can't tell). This photo ends up being used a lot in other articles on the icefish, and I assume that that's because it's on here. But it isn't a great representation of what icefish actually look like. Ambiederman (talk) 16:06, 15 October 2015 (UTC)

Number of species
The article states that "about 25 species of crocodile icefish are currently recognized." However, to my knowledge there are only 16 recognized species.

This was referenced in - does anyone know of a more up-to-date source?

The 16 species is also consistent with the statement that 10 species of icefishes have myoglobin in the ventricle (We know there are 6 species of icefishes that lack myoglobin) Ambiederman (talk) 16:42, 15 October 2015 (UTC)

Antarctic Sea
I don't think there's a body of water called the "Antarctic Sea." I think it should be revised to say the "Southern Ocean." This source puts the range at -1.8 to +2.0 degrees Celsius. Ambiederman (talk) 19:02, 15 October 2015 (UTC)Ambiederman 19:00, 15 October 2015(UTC)

Diet
I think the statement on diet should include a reference. This review article examines the feeding behavior of several icefish species. They found that all the icefishes were piscivorous, and several ate krill as well. None of the species studied ate copepods - does anyone have a source on icefish eating copepods? It also might be worth better explaining the eating habits of these species, as was outlined in this review. Because these fish are not particularly active, they can survive on long periods in between feedings, and many species can consume other fishes up to 50% of their own body length. Ambiederman (talk) 19:30, 15 October 2015 (UTC)

Body length
Does anyone know where we can find a reference on the final adult body length (25-75 cm)?

The closest comprehensive study and/or review I could find was this. The authors don't actually state if they were measuring only adults in this study (although the discussion indicates to me that they were not). Still, perhaps the maximum length data from this study could be used as an indicator of maximum adult body length? Their results indicated that the different species' maximum size ranged from about 22-50 cm (They studied 11 species, so this isn't totally comprehensive).

For what it's worth, I just looked through my field data and found that our specimens (all adults) fell within the following ranges: Chaenocephalus aceratus: 35-80 cm; Pseudochaenichthys georgianus: 45-55 cm; Chionodraco rastrospinosus: 25-40 cm; Champsocephalus gunnari: 35-50 cm Ambiederman (talk) 01:35, 16 October 2015 (UTC)

Oxygen-carrying capacity
This seems like it was the earliest study on comparisons of oxygen content between white-blooded and red-blooded notothenioids, and it's been cited in other articles that mention this trait. I think it would be good to add the reference to this article. Ambiederman (talk) 02:24, 16 October 2015 (UTC)

Adult vertebrates
The article states "Channichthyidae are the only known vertebrates without hemoglobin." However, almost all the literature states that icefish are the only known vertebrates to lack hemoglobin as adults. I can't actually find a source, however, on any other species that lack hemoglobin during development, but my instinct says that this article should probably add the "as adults" statement since it seems to be the consensus among biologists in the field. Does anyone know of any literature that directly addresses this? Ambiederman (talk) 03:15, 16 October 2015 (UTC)

Hemoglobin as oxygen transporter
Article states that Hb is "an oxygen transport protein in the blood." I think this should be changed to "the oxygen transport protein in the blood" since there aren't any other proteins that perform this function in the blood. This way, the critical importance of Hb (in most vertebrates) is emphasized. Ambiederman (talk) 03:17, 16 October 2015 (UTC)

Alpha/beta subunit genes
The article states: "Almost all of the alpha and beta subunit genes have been lost..." This statement could be more precise. The beta subunit gene has been completely deleted, and the alpha subunit gene has been partially deleted. Ambiederman (talk) 03:28, 16 October 2015 (UTC)

Source of myoglobin loss
The section on Mb currently reads, "Myoglobin has been lost[clarification needed] in icefish heart ventricles at least four separate times and by four different mechanisms.[2]"

I think we need to clarify that the loss of Mb in these species is regulated through gene expression, rather than an actual gene deletion. This is also a problem in the "Evolution" section, which states that these species "(lost) their myoglobin genes by a similar process." They didn't actually lose their genes, and it wasn't really a similar process. This is a great source on Mb expression. Ambiederman (talk) 03:51, 16 October 2015 (UTC)

Word choice
The word "supposed" is used twice in this article: "In the past, their scaleless skin had been widely supposed to help absorb oxygen." and "The loss of hemoglobin was initially supposed to be an adaptation to the extreme cold."

The second sentence confused me a bit at first, because suppose has two different meanings: "supposed to" could mean "thought to" or it could mean "meant to." (indicating that something is necessary). In both cases in this article, the word is used with the first definition. Personally, I read the second sentence using the second definition - and I was confused, because we know the loss of Hb isn't really an adaptation in the traditional sense.

Maybe this is just a stylistic difference, and if I'm in the minority then it shouldn't be changed. But I think these sentences are clearer:

"In the past, it was widely believed that their scaleless skin enhanced oxygen absorption."

"The loss of hemoglobin was initially thought to be an adaptation to the extreme cold." Ambiederman (talk) 04:08, 16 October 2015 (UTC)

images
one suggestion I would make would be to add more relevant images. For example, a picture of the enlarged hearts in comparison to a fish's heart that contains hemoglobin and myoglobin Jalashiareliford (talk) 03:17, 13 September 2020 (UTC)

nesting icefish
is this related https://edition.cnn.com/2022/01/13/world/icefish-colony-discovery-scn/index.html — Preceding unsigned comment added by 85.149.83.125 (talk) 15:55, 13 November 2022 (UTC)