Glossary questions and requests

[Jools]

T-Position: The manner in which some Callichthyidae catfishes breed. So named because the breeding pair look as if they are forming the English alphabet letter "T." Also see Ventral Fin Basket.

Ventral Fin Basket: A clamping of the ventral fins by the female of some Callichthyidae catfishes so that she may carry fertilized eggs. Also see T-Position.

For both I'd use "some corydoradine catfish". Bear in mind we only use catfishes when discussing more than one family and I think it better restricted to the sub-family as we don't actually know how some of these fishes spawn and others build bubblenests etc. Oh, bubblenest!

Also, the alphabet containing the letter T doesn't belong to the English speakers. I know what you're trying to say, how about western alphabet? What you write is perfectly correct mind you, as the English alphabet does have a letter T! Just trying to be inclusive.

Jools

[MatsP]

But why not just say "The letter T", as anyone reading this would presumably be using some western-european-ish alphabet anyways, and thus understand the meaning of it. If it's being (machine-)translated to any other alphabet, it's probably going to be relatively meaningless anyways, whether you mention alphabets or not...

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Mats

[Jools]

Yeah, that's simpler...

Jools

[bronzefry]

Jools,
We put bubblenest in. But not:
Labyrinth Organ: Also called "Accessory Breathing Organ." A lung-like apparatus found in certain fishes which allows them to breath air.

I'll re-input ICZN when I get a moment.

T-Position: The manner in which some Corydoradine catfishes breed. So named because the breeding pair look as if they are forming the letter "T." Also see Ventral Fin Basket.

Ventral Fin Basket: A clamping of the ventral fins by the female of some Corydoradine catfishes so that she may carry fertilized eggs. Also see T-Position.
Amanda

[MatsP]

Some new ones:

This is grossly simplified, but that's the way we want it, right?
Metabolism - The biochemical process in which an organism converts food into cell-building, energy and waste.

Here's much more info, perhaps we can link to it...
http://en.wikipedia.org/wiki/Metabolism

Metabolic rate - The rate, or speed, with which the metabolism is performed, higher meaning more processing in a given time.

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Mats

[bronzefry]

Good ones, Mats. What is interesting is the "more" button. The Wikipedia link may turn up. Here's another basic one:
Fertilization: The process where a female reproductive cell and a male reproductive cell successfully join to form offspring.
Amanda

[bronzefry]

Electric Organ: An organ found in some catfishes that sends out an electrical signal to locate food, prey and/or locate position in murky water.

Ectotherm: A species whose body temperature is determined by its surroundings, i.e. "cold-blooded."
Amanda

[sidguppy]

Strangely enough, AFAIK the Electric Cat is fairly unique of all electric freshwater-fishes because it does NOT navigate or communicate with the help of the electric organ.
at least not on the finetuned level of the Gymnotids or Mormyrids!

with this fish it's use is for killing prey and defensive purposes.

the Electric Rays (Torpedo spp) use it in a similar manner.
wich makes sense; setting up a continuous electric field or current in salted water would consume immense quantities of energy. strong currents of electricity "leak away" in salted water; it goes EVERYWHERE, it doesn't stay in a neat "oval" around the fish, like the field around a Gymnotid Knifefish or Mormyrid Elefantnose-fish in a river or swamp.
Also in such a mineral-rich environment a fish might "shortcut" itself, not likely to happen in the mineral-poor blackwaters of Amazonias or the Central African rainforests.

Electric Rays DO use special organs to search for prey; like sharks they have organs that sense the tiny electric currents in the nerve systems of a buried or sleeping fish. these organs are NOT "electric" organs, but more like "electric detecting organs".

It's therefore not a surprise that the Electric cat is one of the very few if not the only electric fish native to Lake Tanganyika, IN the lake, not just the affluents.
the water of Tanganyika is very high on "salts/minerals" and has a high conductivity.
Mormyrids rarely dwell in the 2 mineral-rich Riftlakes (they're known from all 3, but Lake Viktoria has water more like riverine habitats, unlike Malawi and Tanganyika) but almost always the surrounding swamps, rivers and streams; not the lakes proper.

navigating is done the ol' catfish style: lateral organs and whiskers. communicating is likely done by sound and/or smell, also very common with most catfish.

[bronzefry]

Sid, thanks very much!
Let's try it this way:
Electric Organ: An organ found in some Rift Lake catfishes that sends out an electric signal to locate food. In other types of fishes, an Electric Organ may send out a signal to locate food, prey and/or sense location. Also sometimes called "Electric Detecting Organ."

Gestation: The time between fertilization and hatching.
Amanda

[Marc van Arc]

Electric Organ: An organ found in some Rift Lake catfishes that sends out an electric signal to locate food.

Amanda, I think this is what is meant:
An organ found in Malapterurus spp. that sends out electric signals to kill prey or to defend themselves.

The Rift Lake part narrows it too much, as riverine Malapterurus will use the same tactics as well.

[Silurus]

Electrogenic (electricity-generating) and electroreceptive (electricity-sensing) organs are not the same structures. An electrogenic organ has no capacity to receive the electric signals it sends.
Quite a number of catfishes are electroreceptive, and some (besides malapterurids) are also very weakly electrogenic (e.g. in clariids).

[bronzefry]

Electrogenic (electricity-generating) and electroreceptive (electricity-sensing) organs are not the same structures. An electrogenic organ has no capacity to receive the electric signals it sends.

Thank you, Silurus. Thank You, Marc. We're trying to stay away from species names since they change so often. I'll define "electrogenic organ" and "electroreceptive organ" to avoid confusion.
Amanda

[sidguppy]

Electrogenic (electricity-generating) and electroreceptive (electricity-sensing) organs are not the same structures

Thanks for sorting that out Silurus!
I couldn't find the right words.
The electroreceptive organs are the ones I meant by giving the shark example; searching for prey by "listening" for nerve-signals in living, buried fish.
now I could also dig up the name of those orangs: Ampullae of Lorenzini.
are they the same as in Clariids? or are we talking convergent evolution here?

btw I leave it to the word-wizards to rehassle the definition I found (I'll quote it at the end of this post) for catfishes, but that one might be useful as well in that list, if it isn't added alredy; plenty examples of convergent evolution in several catfish-families.
for example the suckermouths of the Loricariids and Chiloglanis or Euchilichthys; the armourplating in Loricariids, Doradids and some Amphiliidae or the overall built of large Bagrids and large Pimelodids.
there's a finite number of body-build-up solutions for a certain niche.....

convergent evolution: The evolution of species from different taxonomic groups toward a similar form; the development of similar characteristics by taxonomically different organisms.

[MatsP]

As HH used a word in the side-bar of the article in PFK that I didn't know, I thought I'd post the definition:

Sessile - To be permanently attached to the base. In fishkeeping terms, this is used to indicate fish that stay in one place at the bottom, and rarely moves, like Chaca spp.

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Mats

[MatsP]

Since someone asked about it earlier:

Paired fins - A term used to indicate the fins that are in pairs on the fish: The pectoral and ventral fins.

--
Mats

[bronzefry]

Here's another:
Anoxia: A lack of free oxygen.

Electroreceptive Organ: An organ present in some fishes that allows "listening" for electrical signals.

Electrogenic Organ: An organ present in some fishes that generates an electric current to locate food and/or prey.

I found sessile in another book with the same definition. I'll put that in today. Should we define evolution before inserting the definition of convergent evolution? I know I'm being fussy, but....
Evolution: When plants and animals descend with modifications.
Feel free to make corrections or add your thoughts!
Amanda

[Jools]

Evolution: When plants and animals descend with modifications.

I think we need more than that! What's the OED defn?

Jools

[bedwetter]

Noted an error in the definition for bloodworm.(currently ="Mosquito larvae used as fish food.") Bloodworms are not mosquito larvae, but the larvae of midges of the family Chironomidae.

so, definition could be
Bloodworm: Aquatic larvae of non-biting midges of the family Chironomidae (Diptera), commonly used as fish food. Red colour is due to presence of haemoglobin, an adaptation for living in low-oxygen waters. Often incorrectly called red mosquito larvae.

Jeff

[MatsP]

Evolution - When new traits occur in a plant or animal, and this trait is passed from generation to generation.

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Mats

[bronzefry]

Jeff, thanks for the correction.

In Brian Coad's dictionary, evolution is defined as "descent with modification." Webster's definition is "the development of a species organism, etc. from its original state to its present state." John Tullock in the Dictionary of Aquarium Terms defines evolution as "biological change resulting in the development of new species from ancestral species due to natural selection acting upon genetic variability in the latter." The last one seems quite complicated.

I'll put Paired Fins, Anoxia, Electroreceptive Organ and Electrogenic Organ in today. I want to let the new bloodworm definition sit for a day or so to see if there's anymore input. Thanks again, Jeff!
Amanda

[MatsP]

Amanda,

I agree with Jeff's definition of bloodworm.

And some new ones:
Phenotype - the characteristics of an organism, based on genetical inheritance. In humans eye-colour (blue or brown) is such characteristic. Albinism or long fins are examples in fish.

Recessive gene - One of a pair of genes that form the offsprings phenotype, that requires a match on the other gene too. E.g. albino genes are recessive, so only if the gene from both parents are "albino" will the offspring be albino.

Dominant gene - One of a pair of genes that, when comhined with a recessive gene hides the trait of the recessive gene. For example, the offspring of one albino and one non-albino parent would be non-albino, yet carries the gene for albinism.

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Mats

[Jools]

I like Tullochs defn of evolution as it doesn't make me feel like I need to go and look up other terms to understand it.

Jools

[bedwetter]

Personally, I don't agree with Tullocks definition of evolution because it stresses only the development of new species. Evolution is any change in the genetic make-up of a population over time. This may not neccessarily result in the formation of new species.
I like mats' definition of evolution, but perhaps it could be changed to say 'organism' rather than 'plant or animal'.

Also, I think Mats' definition of dominant and recessive need a little of bit modification. Genes are not dominant or recessive, it is the different forms of genes (called alleles) which are dominant or recessive. So, in the case of albinism, there is one gene that controls pigmentation. The dominant allele 'codes' for normal pigmentation, the recessive for albinism.

So, maybe:
Gene: a region of DNA that determines a certain trait of an organism i.e. pigmentation or fin length. There are two copies of each gene (or alleles) in each organism, one inherited from the mother, one from the father. See also allele.

Allele: alternative forms of genes. i.e. For the gene controlling pigmentation, there are two forms: 'normally pigmented' and 'albino'.

Dominant Allele:: A form of a gene which only requires one copy to be expressed, generally represented by a capitol letter i.e 'X' (in contrast, the recessive allele is represented by 'x'). For the gene controlling pigmentation, the dominant allele codes for normal pigmentation (=X). An organism will be normally pigemented if it has two copies of the dominant allele 'XX' or if it only has one copy of the dominant allele 'Xx'.

Recessive Allele: the form of a gene which will only be expressed if both copies of the gene are recessive. Generally designated by a small letter i.e 'x'. In the case of pigmentation, the form of the gene which codes for albinism is recessive (='x'), whereas the allele for normal pigmentation is dominant (='X'); an organism will only be an albino when both copies of the gene are recessive 'xx'. If an organism is 'Xx', the dominant allele X will be expressed.

These are bit longwinded. Maybe someone can think of a way to word them better.

Jeff

[bronzefry]

Let me put the reworked bloodworm definition in today. I'll look through the new words and rework Tullock's definition of evolution. I have a few days off (finally!!!) so I can look for more words. Great work, everybody!
Amanda

[skh]

Hi,

my first entry.

Hypoxia: The actual oxygen concentration is lower than the oxygen concentration of water fully equilibrated with air.

Hyperoxia: The actual oxygen concentration is higher than the oxygen concentration of water fully equilibrated with air.

cheers

Stefan

[Deb]

Carl Ferraris' well-known book, Catfish in the Aquarium begins with a quote from Dr. Archie Carr:

"Any damn fool knows a catfish!"

True? I think we need a definition of the word catfish. I'll start if off by saying that every catfish has at least one pair of barbels, and that no catfish has scales.

Deborah

[Shane]

I think we need a definition of the word catfish.

The world needs a better definition...

I'll start if off by saying that every catfish has at least one pair of barbels, and that no catfish has scales.

Not all have barbels. There are some pretty good definitions, but all use internal characteristics. Coming up with a definition of "catfish" based on external characteristics is tough.
-Shane

[Deb]

Ferraris writes that some catfishes have barbels which are hidden in the grooves of their cheeks, but that's not what you mean, is it? Well, if we can't use barbels (never on the upper lip) as part of the ID, you're right - it will be tough. Impossible for me.

Deborah

[racoll]

A few from me.....

Lotic - Running water (streams, rivers etc)

Lentic - Still water (ponds, lakes etc)

Symbiotic - An association of two different organisms, which brings mutual benefit. eg the wood eating Panaque spp. and their gut microorganisms.

[racoll]

I'm not quite sure that aufwuchs is correct. I'm not a German speaker, so i'm not too sure exactly what it means. Wels Altas I refers to it as...

"Biocover. Largely, the layer of filamentous algae growing on hard substrates, and the tiny invertebrates living within"

Now, this is different to the definition of biofilm, which most people regard as the same as aufwuchs. Was aufwuchs a term created by German aquarists, not scientists?

I think perhaps this needs to be cleared up.

My definition of biofilm is...

"An adhesive microscopic layer coating all (but mostly hard) submerged surfaces, comprising of mainly the following microoganisms; bacteria, algae and protozoa. Along with it's associated invertebrate epifauna, it is a common food source for many loricariid catfish".

Hmmmmm, maybe that's a bit too long?