Transcript Ch 26_27_28 Sponges_ Cnidarians_ _ Worms

Kingdom Animalia
Invertebrates
Kingdom Animalia
Eukaryotic
 Multicellular
 Heterotrophic
 No cell walls
 Motile
 Embryo Development

Animal Phylogeny
Cnidaria
Porifera
Nematoda
Platehylmenthys
Annelida
Mollusca
Echinodermata
Arthropoda
Chordata
Chapter 7: Invertebrates
100
80
60
Invertebrates
Vertebrates
40
20
0
All Animals
Phylum Porifera
“Pore-bearer”
 Sessile = attached
 Parazoa = no tissue
 5,000 modern species




150 freshwater
Intertidal to 29,000 ft
Evolved over 500 mya
from protozoans
Sponge Anatomy
Ostia: many pores
 Cells

Pinacocyte: flat cell
 Porocyte: pore cell
 Choanocyte: collar
cell – has flagella


Osculum: opening
Feeding
Filter feeders
 Organic
particles &
plankton
 Choanocytes collect
 Amoebocytes
-carry

Physiology
No tissues = no organs = no organ
systems
 Digestion - choanocytes
 Circulation - water current
 Diffusion

Waste Removal
 Respiration

Reproduction

Asexually

Budding



External = bud outside
body - break away or
stay connected
Internal = archaeocytes
collect and become
surrounded by spongin
– Gemmeule
New sponge has exactly
the same genetic
material as the parent
= clone

Sexually




Hermaphroditic
Don’t fertilize their
own eggs with their
own sperm
Spawning
Free-swimming larva


Cilia
Larva settles on the
sea floor, becomes
sessile and grows
into an adult.
Classes

Demospongia – spongin




Largest class (90%)
Much diversity and
vairety in shape and
color
Most marine
Calcara – bony





Variety in shape
Shallow tropical waters
Small
Mesh or honeycomb
skeleton
Lack hollow canals =
stronger

Hexactinellid - glass




Uncommon
Cup-shaped with
sturdy internal
skeletons
Can’t contract
Conduct electrical
impulses

Optical fibers
Class
Demospongiae
Class
Calcara
Hexactinellid

Uses
Medicines



Tools


Dolphin Article
Sponges for cleaning



Maceration - bacteria
eat away the cells
leaving just the spongin
Fisheries in the
Mediterranean & West
Indies
Synthetic sponges has
reduced the commercial
sponge fishing industry

Antimicrobial compounds
from bacteria
60% biomass is bacteria
Current Medicines –
www.marinebiotech.org






Vidarabine - anti-viral drug
(Herpes)
Ara-C - anti-cancer drug
Halichondrin B - anticancer drug
Discodermolide – breaks
down solid tumors
Agelasphins - antitumor
and immunostimulatory
properties
Contignasterol - asthma
and inflammation of the
skin and eye
Cnidarians
Forms
•
Cnidarians (coelenterates) occur in two
basic forms:
Polyp: sac-like attached
stage with the mouth
and tentacles upward.
 Medusa: sac-like structure
with tentacles hanging
downward;
upside-down polyp

Physical Characteristics
1.
Radial Symmetry
Physical Characteristics
(cont.)
2. Anatomy
Exoskeleton or Endoskeleton: made of
chitinous, calcareous, or protein in some
 Gastrovascular System: with a single
opening that serves as a mouth and anus;
tentacles encircling mouth
 Nerve net: nerve cells connected
throughout
body; statocysts tell sense of balance

Physical Characteristics
(cont.)
3. Tissues performing specific
function




Epidermis: external layer of cells
Gastrodermis: internal layer of cells
Mesoglea: gelatinous middle layer
(usually doesn’t contain cells)
Nematocysts: specialized stinging cells
for defense & attacking
Hydrozoa
•
Mainly consist of bushy or feathery colonies of tiny
polyps.
•Siphonophores:
form drifting colonies of polyps; some
have specialized floats
(i.e. Portuguese Man-o-War)
Scyphozoa
•
•
•
•
•
•
These include the larger jellyfish.
Common in all oceans
Large medusae are the dominant stage of this class
Polyps are very small and release juvenile medusa. Few
species skip polyp stage altogether.
Swim with rhythmic contractions of rounded body, or bell.
Known to give fatal or lethal stings.
Anthozoa
Solitary or colonial polyps that lack
medusae stage.
•Include Sea anemones (colorful large polyps),
Sea pens, and Corals (colonial anthozoans).
• Some corals include gorgonians (sea fans),
precious corals, and black corals.
•
(c) 2007 brainybetty.com ALL
RIGHTS RESERVED.
30
Worms
Bilateral Symmetry

Allows for animal to be more active in the
pursuit of prey.
Excretory & Nervous
Systems
 Most worms have an excretory system:
complete with mouth, gut, & anus
 Worms have a complete nervous system:

Most have eyes & brain with nerve cord
running along its body
Main Worms
1)
2)
3)
4)
5)
6)
Six Main Types
Flatworms
Ribbon Worms
Nematodes
Segmented Worms
Peanut Worms
Echiurans
1)Flatworms
About 20,000 species; most carnivorous & free swimming
1. Flukes

2.
Largest group of flatworms; Mainly parasitic living in organism
– Adult attaches itself to intestine of organism.
– Produces Eggs in large quantity.
Tapeworms


Parasites that have long body of repeated units. Head attaches
to organism with suckers.
Lacks a mouth & gut. Ingests nutrients
through body.
2)Ribbon
Worms
Look like long flatworms, ribbon-like
 Complete digestive tract
 Circulatory system: blood transports nutrients &
gases to tissues
Most Unique Feature
 Proboscis: long, fleshy tube used to entangle prey
 Longest Invert on earth: reaches 30 m (100ft) long

2)Ribbon
Worms
There are ~900 species, mainly marine.
 Found in all oceans, most nocturnal
 Incredibly elastic, with proboscis extending a
meter past body.
 Longest Invert on earth: reaches 30 m
(100ft) long

3)Nematode
 Known as the Roundworms
 Mainly parasitic and marine
Larva found on many fish and can be eaten
 Adapted to live in sediments or in organisms
 Hydrostatic Skeleton: has fluid filled cavity
covering the gut, which transports nutrients;
aides in support & locomotion

Segmented Worms
4)
Known as Annelids; contain ~20,000 species
 Anatomy

Segmentation: body consists of series of compartments,
or segments
 Gut goes through all segments and lies in a cavity called
the coelom. It’s filled with fluid and divided by partitions,
which act as hydrostatic skeleton and can be contracted
by means of muscles in the body wall.
3 main types: Polychaetes, Oligochaetes, & Leeches


5)Peanut Worms
(Sipunculoidea)
Soft unsegmented bodies
 All are marine & live in mud, rocks, corals, or
empty shells
 Anterior portion contains the mouth and set of
branching tentacles, which can be contracted
into body, making it look like a peanut.

6)Echiurans
 Look like soft unsegmented sausages buried in
mud or coral.
 Look like Peanut Worms, except for nonretractable , spoon-like or forked proboscis.
 Deposit Feeders: Use proboscis to feed