Feeding is the process of obtaining nutriends and can be modulated by the needs of the individual. This
is a study with beetles. They fed them one of two diets for one week either a lipid rich or a protein rich
diet. After a week they let them choose if they wanted to lipid rich or protein rich food. The beetles that
were eating a lipid rich food started loading up on protein rich food and vice versa. They need to get the
other nutrients that they were deprived of and so the nutriend needs are modulated by the needs.
The beetles were fed either a lipid –rich or a protein –rich food. When you give them a choice later, they
choose the other category because they have been deprived of it and they need it. The
This is a tape worm, they are endoparasites and live in the gut by sticking on to your gut. They just
absorb nutrients through their body.
The head end called the scolex has sucking discs, so they can bite on to the intestinal wall and allow the
tube to float around absorbing food
Body is made up of repeated segments.
- Each segment is called a proglottids, they have no gut and so they just absorb everything
through the walls and all this stuff in the segments are their gonads (for reproduction)
- They passively absorb their nutrients
- Tapeworms are primarily gutless, they never had a gut through their ancestors
Sac = externa for incubation of eggs....infestation prevents crab from molting and so prevent diversion
of energy away from parasite as well as leads to castration, crab cares for eggs as if their own
- The white barnacles on the left are just regular parnacles and they have the largest penis size
per body size
- The one on the right is a crab with an egg sac, full of parasatic barnacles
- The parasatic barnacle takes over the crab and stop the crab from molting and make an egg sac
and force them to look after the parasitic barnacle’s eggs
- The barnacles on the right are the parasitic ones, and they are the larval stage
- They basically have a mass of undifferentiated mass and approach a host and inject that mass of
cells into it
- The cells are actually the parasitic barnacles, spread across the host and take in the nutrients.
They have no gut, they just absorb it passively through the body walls
- The barnacle on the left (the 2 pictures) have a gut however
- The parasatic barnacles are secondary gutless, they had a gut and through evolutionary times
they lost it because they did not need it anymore.
- The egg sac is full of parasatic barnacles, they Infect the crab and forces them to look after their
- Barnacles at the larval stage are free swimming organisms
- The parasitic barnacles have a mass of undiffreniate cells which is injected into the crab and is
the barnacle that takes over the crab body
- They absorb nutrients through the body surface
- The parasitic barnacles are secondary gutless, means they lost their gut through evolution Slide 5:
They are filter feeders, they pass the water through their body and filter what they want to eat
The osculum is where the water is flowing out
The water is coming through porocytes in to the central cavity spongocoel
The choenocytes (collared cell) filter out all the foods they want
- It has a single flagallum is constantly beating and is what causes the water to flow through the
collar and out, there is a mesh like nature in the collar
- The collar is lined with mucous which traps the food particles
- This seperates food from the water
- The food particles are engulfed by phagocytosis, which travel through to the amoebocyte which
carries out the digestion of the food
They are chordates and invertebrate
They have large openings and a small opennings,
The water comes through the big one and out through the small ones
The upper opening is called the buccal siphon(water in)
And the small one is called the atrial siphon(water out)
They have a gut (the blue structure) which is actually the pharynx with many slits.
The food gets separated from the water in the pharynx, which is coated with a mucous and is produced
at the endostyle.
The pharynx is ciliated, and the cilia pushes the mucous from the endostyle to the gutter, moving from
the endostyle to the gutter coating all the splits
The water flows through the slits and out through the atrial siphon
The food gets caught in the mucous in the pharynx
The gutter rolls up the mucous, and that mucous is full of all the food that is trapped and gets pushed
into the gut where all the digestion occurs.
Baleen whales (non-tooth whales)
They have pleats at the bottom of the animal’s body surface, they are huge.
These pleats allows for large amount of expansion of the oral cavity allowing for more water to be taken
in during a single gulp
They have baleen plates instead of teeeth, and help them separate the water from the food. They are
made up of keratine like our hair and what not.
The are going to open their mouth as wide as possible, take in a large amount of water-> Close their
mouth and use their tongue to compress their oral cavity-> the water is going to pass out though the baleen-> Whatever cant get passed through get stuck and they just scrape it up with their tongue and
digest it in their stomach.
Their jaws are very flexible.
- The jaw is joined very loosely to their skull allows them for them to open it wide (loose
articulation), they joint is very elastic and allows
- The other set of whales have teeth to seize water animals they can feed on
They pharynx is the major organ used for their feeding. They use it to penetrate into the body wall of
the prey and suck out all the body fluids.
Many of these animals will pump out enzymes that will break the tissues up to allow for a better fluid
They latch on the p