08-19-2017, 06:55 PM
Fish of the IDU
The term "Fish" is not a 'scientific' one, it is just a colloquial label applied to the members of five surviving Classes and three extinct ones that all belong to the Phylum Chordata & Sub-phlum Craniata but whose relationships to each other have not yet been fully determined.
The extinct classes were the Ostracodermi, Placodermi, and Acanthodii. All three would have had members present in waters around what is now the Iduvian Region for varying proportions of the Palaeozoic Era, but would have died out here -- as they did in RL -- before the "Age of Dinosaurs".
(Class Myxini)
(Order Myxiniformes)[= Hagfish]
=> (Family Myxinidae)[= Hagfish]
(The Idu region almost certainly has native populations of one or more species from this [relatively obscure] group, and those almost certainly belong to the same order and family as do all of their RL-Earth relatives. However as their species don?t differ much in either appearance or ecological niche, they don?t really have any direct interaction with people, and they aren?t one of the groups about which I already have some ideas, it seems to me that there isn?t any point in going into further detail here while there are still more interesting groups on which to work? unless anybody else here is particularly interested in them?)
(ClassPetromyzontida)
(Order Petromyzontiformes)[= Lampreys]
=> (Family Petromyzontidae)[= Northern Lampreys]
(The various species of lamprey with native populations in the Idu region probably all belong to this [ancient] family, like their counterparts from RL-Earth?s northern hemisphere: The other two families with extant species on RL-Earth are both restricted to relatively small areas in the southern hemisphere, with which our lands have had little if any contact, and so neither of them seems likely to be represented here. Also, as as this particular family has lasted for a very long time on RL-Earth without its members diverging very much, I think that its descendants in the Idu waters wouldn?t have diverged enough for reclassification as an endemic family. It also seems reasonably likely to me that any species which spend part of their life-cycle in the open seas actually belong to the same genus as their RL-Earth equivalents, although some or all of the species whose members spend their entire lives in fresh water ? and therefore travel less ? might belong to endemic genera rather than to ?shared? ones. The individual species, however, I suspect are mostly [if not completely] endemic?)
=> (Family Geotridae)[N/A]
=> (Family Mordaciidae)[N/A]
The term "Fish" is not a 'scientific' one, it is just a colloquial label applied to the members of five surviving Classes and three extinct ones that all belong to the Phylum Chordata & Sub-phlum Craniata but whose relationships to each other have not yet been fully determined.
The extinct classes were the Ostracodermi, Placodermi, and Acanthodii. All three would have had members present in waters around what is now the Iduvian Region for varying proportions of the Palaeozoic Era, but would have died out here -- as they did in RL -- before the "Age of Dinosaurs".
(Class Myxini)
(Order Myxiniformes)[= Hagfish]
=> (Family Myxinidae)[= Hagfish]
(The Idu region almost certainly has native populations of one or more species from this [relatively obscure] group, and those almost certainly belong to the same order and family as do all of their RL-Earth relatives. However as their species don?t differ much in either appearance or ecological niche, they don?t really have any direct interaction with people, and they aren?t one of the groups about which I already have some ideas, it seems to me that there isn?t any point in going into further detail here while there are still more interesting groups on which to work? unless anybody else here is particularly interested in them?)
(ClassPetromyzontida)
(Order Petromyzontiformes)[= Lampreys]
=> (Family Petromyzontidae)[= Northern Lampreys]
(The various species of lamprey with native populations in the Idu region probably all belong to this [ancient] family, like their counterparts from RL-Earth?s northern hemisphere: The other two families with extant species on RL-Earth are both restricted to relatively small areas in the southern hemisphere, with which our lands have had little if any contact, and so neither of them seems likely to be represented here. Also, as as this particular family has lasted for a very long time on RL-Earth without its members diverging very much, I think that its descendants in the Idu waters wouldn?t have diverged enough for reclassification as an endemic family. It also seems reasonably likely to me that any species which spend part of their life-cycle in the open seas actually belong to the same genus as their RL-Earth equivalents, although some or all of the species whose members spend their entire lives in fresh water ? and therefore travel less ? might belong to endemic genera rather than to ?shared? ones. The individual species, however, I suspect are mostly [if not completely] endemic?)
=> (Family Geotridae)[N/A]
=> (Family Mordaciidae)[N/A]

