Goldfish Internal Anatomy



(click image for larger view)

Mouth
Food is ingested through the mouth, but the mouth also takes in fresh water.  This water is continually pumped over the gills to extract oxygen from it, and then expelled through the operculua.

Pharynx
The pharynx is located at the very back of the mouth, and this is where the fish grinds up food particles into smaller pieces for digestion.



Pharyngeal Teeth
The pharyngeal teeth are located on the lower surface of the pharynx.  These teeth are continually shed and replaced throughout the fish’s life.

Chewing Surface
Above the teeth, on the upper surface of the pharynx, there is a hard chewing surface used to grind the teeth against.



Gill Arches
Gill arches are bony structures that support the delicate gills.  The forward projections (look like spikes) on the gill arches are called gill rakers.  These gill rakers serve the purpose of straining out food and debris in order to protect the delicate gill filaments.

Gills
Gills are composed of filaments containing capillary beds for gas exchange.  They allow the fish to take in oxygen and expel carbon dioxide.



Heart
The goldfish heart is two-chambered, having one ventrical and one atrium.  It pumps deoxygenated blood to the gills for oxygenation, and throughout all other organ systems of the body.

Liver
The liver aides digestion by excreting digestive enzymes, stores fats and carbohydrates, and also destroys old blood cells.



Gallbladder
The gallbladder stores bile produced by the liver.

Intestines
Goldfish have no stomach for food storage, but the beginning section of the intestine, called the intestinal bulb, functions as temporary food storage in addition to absorbing lipids from food items.  The second section of the intestine, called the caudal intestine, is narrower and absorbs protein from food items.



Spleen
The spleen stores blood and recycles old red blood cells.

Gonads (Testes/Ovaries)
The gonads, or reproductive organs, are located underneath the swim bladder.  Females have a single ovary that produces eggs, and males have paired testes for the production of milt.



Swim Bladder (Cranial Lobe & Caudal Lobe)
The swim bladder is a hollow, gas-filled sac that helps the fish maintain buoyancy.  Fancy goldfish can sometimes be prone to swim bladder problems because of their modified, deep bodies.  Their is a duct, called the pneumatic duct, leading from the esophagus to the swim bladder and by using this, goldfish can somewhat regulate the swim bladder by gulping air.

Kidney
The kidneys filter out nitrogenous waste from the blood.

Spine
The spine provides structural support to the body, and also houses the spinal nerve cord.

Brain
The brain is where automatic functions, like respiration, and higher behaviors, like decision-making, occur.  This is where all sensory information is processed.



 
Copyright J.M.Connelly

Dia de los Muertos Goldfish Tank
I thought my goldfish should join in on the holiday fun! Dia de los Muertos (Day of the Dead) is
Read more.
Beginner Mistakes to Avoid | Dos and Don’ts
Do plenty of research before buying anyfish!  This will help you avoid many beginner mistakes and allow you toprovide a
Read more.
What Pet Stores Don’t Tell You About… Cycling
Now I don’t want to make it sound like all pet stores give bad information about fishkeeping, because some are
Read more.
Yujin Goldfish Gashapon Collection
Several months ago I discovered these goldfish gashapons and began collecting them!  Gashapons are Japanese capsule toys dispensed from coin
Read more.
Update on Luca, Felix, and Clover
My new ghost bristols have been getting all the attention lately, so I thought I’d take some time to do
Read more.
Callisto is Declining
Callisto came to live with me on November 10th, 2011.  From day one, she has always been a major surface-gulper. 
Read more.
How To Euthanize a Fish Humanely
Euthanizing our pet fish is obviously something none of us ever want to have to do, but sometimes it’s the
Read more.
Goldfish Growth and Changes Update
Here’s the most recent update: Butterfly Telescope Growth and Changes Today Luca weighs 47 grams, is 2.75″ in body length,
Read more.
Rest in Peace Callisto
Callisto was euthanized last weekend because of her ongoing and worsening health condition.  It was a tough decision to make,
Read more.
New Culling Nets
For my first spawn of ghost bristol fry, I’ve been making do with a regular aquarium net; the dark green
Read more.

One thought on “Goldfish Internal Anatomy

  1. Kris Christian

    Hi my goldfish has poo strings hanging out its vent is this healthy/normal help please

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

*

code