Close-up on Gills

Gills

Most fish rely on gills to take in oxygen. Gills can be covered with flaps, hidden under slits, or carried externally. Take a look at the external appearance of the gills and then take a closer look at the frilly gills themselves.


   Covered gills - Typical fish cover their gills with a flap called an operculum, leaving one opening at the flap on each side of the fish's head. Bluegill has a distinctive "black ear flap" on its operculum. Are those actually "ear flaps"?
Photographer - TBA. Get permission.
   Uncovered gill slits - This Gray Nurse Shark (Carcharias taurus) displays the uncovered gill slits found on sharks, rays and skates. Although sharks can have more gill slits, most sharks have five.
 Photographer - Richard Ling.
Permission by Creative Commons 2.0
Uncovered gill slits - The gills on a Frilled Shark (Chlamydoselachus anguineus) are partly exposed.
  
Public domain.


 More about Frilled Sharks
•  Frilled Shark in natural environment
•  Frilled Shark in captivity shortly before death



Exposed gills - When Armored Bichirs (Polypterus delhezi) are young, they display external gills that are lost as the fish matures.
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Exposed external gills of a salamander.
Note: Salamanders are amphibians rather than fish.


Photogapher -


More about amphibians
•  TBA




Most land animals have lungs, and fish have gills.

Things to note:


  
This Wikipedia and Wikimedia Commons image is from the user Chris 73 and is freely available at http://commons.wikimedia.org/wiki/Image:Tuna_Gills_in_Situ_01.jpg under the creative commons cc-by-sa 2.5 license.

Gills of unspecified fish
Underneath the operculum or flap that covers the gills of fish, you can see both the gill rakers (white comb-like structure) and the attached gill filaments (red fringe). Both of these are attached to the bony structure of the fish by the bony gill arch that is hidden in this image. Water enters throught the fish's mouth, particles are filtered by the gill rakers, passes over the gill filaments where oxygen flows in to the circulatory system like in our lungs, and passe outside through the gill flap.

Source
Permission - TBA.

More about gills
•  Photomicrographs of the parts of a gill on a Fathead Minnow. These show thin-sections of ... stained called histology.
•  Development of gill arches.
Expert symbol •  How to take a hook out of a fish.



Basking shark  Cetorhinus maximus
Source
Permission - TBA.

More about basking sharks

•  Necropsy images