Download Particulate and suspension feeders

Particulate and suspension feeders
Term test answers addressed (in part)
Amphioxus Branchiostoma: filtering with mucus
Lophophores: sabellid worms and sorting
Chaetopterus: Annelida
Posterior face honeybee metathoracic leg
showing basitarsal brush, hint of branching of
hairs
Hairs are branched; pollen transferred from them by
brushes of basitarsus: a tarsal segment enlarged into a
rectangular brush, shaped for this purpose. Cross-body
use of rake at end of broad-tipped tibia draws pollen up
into press. Pollen press compacts and moves pollen to
pollen baskets. See account in lab outline.
There are special features in the
natural world everyone should see.
One of these is a coral reef. The
diverse fishes and invertebrates, all
living their lives for close-up
viewing. The same remarkable
community of animals can be seen
differently at night.
And in complete darkness , turn off
your light at depth and shake your
hand; little speckles of greenish
yellow light occur wherever the
water is agitated. This is the light of
diatoms, tiny single-celled
organisms that phosphoresce.
Noctiluca
large protozoan, a dinoflagellate (allied with the brown algae and diatoms by the presence of
xanthophyll pigments that give them a brown or golden brown colour and by the absence of
chlorophyll b, chlorophylls a and c are present)
Luminescent: principal
contributors to planktonic
bioluminescence
Two flagella characterize dinoflagellates, one
directed posteriorly lying in a long groove called
the sulcus and another transverse called the
girdle
Branchiostoma
amphioxus
Anterior to the mouth of amphioxus is an oral hood defining a
buccal cavity; arching on the underside of the hood are ciliary
tracts called the wheel organ. [The metachronal beating of the
cilia reminded someone of a wheel.] Buccal cirri line the edges
of the lateral aspect of the hood and are used as a coarse filter
to prevent large inorganic particles entering with the incoming
water stream (incurrent). Mucus is discharged onto the wheel
organ from Hatschek’s Pit in the midline of the hood. The
mouth is at the back of the buccal cavity and is bordered by a
velum with velar tentacles.
Within the cavity of the pharynx frontal cilia line the gill bars
and are positioned so that their beating drives a sheet of
mucus produced in the hypobranchial (ventral) groove up the
inner wall of the pharynx. Projecting into the space between
gill bars (gill slits) are lateral cilia whose beating creates the
current . Food particles adhere to the mucus and travel in the
mucus sheet [held against the pharynx wall by the current] up
the pharynx walls to accumulate and travel rearward in a dorsal
groove (epipharyngeal), thus reaching the intestine just beyond
the pharynx.
Oral hood
Buccal
cirri
atriopore
Bryozoa
colonial tiny animals in
their own phylum that
filter feed with
lophophores, a whorl of
tentacles surrounding the
mouth
Bryozoa [moss animals]: lophophores
A circular or horsehoe-shaped fold of the body wall that encircles the mouth and
bears numerous ciliated tentacles (Barnes)
A number of phyla are
notable for
lophophores: have
been grouped together
and called the
‘lophophorates’:
Phylum Bryozoa
Phylum Entoprocta
Phylum phoronida
Phylum Brachiopoda:
this last being
lampshells, Lingula (in
lab)
Lampshell
Chaetopterus
Chaetopterus in its u-shaped burrow
Filter feeding in annelids: sabellid
worms ‘fan’ or ‘feather duster’ tubedwelling worms