Kingdom Animalia

Kingdom Animalia

• Eukaryotic (Domain Eukarya)• All Multi-cellular (unlike Protists)• All Heterotrophic (unlike Plants)• No cell walls (unlike Fungi and Plants)• Sexual reproduction• Cells are organized into structurally-functional

tissues

Marine Animals Without A Backbone

• There are two major groups of animals: the vertebrates, which have a backbone, and the invertebrates, those without a backbone

• Of all the species of animals, ~97% are invertebrates!

Marine Animals Without A Backbone

• All major groups of invertebrates have marine representatives, and many are exclusively marine

• Other than insects – one of the few invertebrate groups to invade land – most animals are marine!– ~8/10ths of all organisms

are Arthropods!

if Facebook existed years ago…

Phylum Porifera

• Sponges are the simplest of all animals; best described as aggregations of specialized cells

• Sponges do not have true tissues or organs; cells are largely independent of one another

• All are sessile (non-mobile)• Porifera means “pore bearer”• NO body symmetry

Phylum Porifera

• Tiny pores, or ostia allow water to enter and circulate through a series of canals where plankton and other organic debris are filtered out and eaten

• Sponges are suspension feeders, animals that eat food particles suspended in the water column

• Filter feeders; they actively filter out food particles

Phylum Porifera

• Water is pumped into a feeding chamber lined with collar cells, or choanocytes

• Choanocytes have a flagella that generates a current, and a thin collar that traps food particles

• Food is then ingested within the cell

Phylum Porifera

• As sponges get larger, they need structural support

• Most have spicules, supporting structures of different shapes and sizes, made of silica or calcium carbonate

• Many also have a ‘skeleton’ of tough, elastic fibers made of a protein called spongin

Phylum Porifera

• Wandering cells, or amebocytes secrete the spicules and spongin

• Amebocytes also transport and store excess food particles, and can change into other cell types, quickly ‘repairing’ any damage to the sponge

• ~80% of food particles are engulfed and ingested by choanocytes; smaller particles, inc. bacteria and dinoflagellates are eaten by amebocytes

Sponges are filter-feeders

You are what you eat…

• The silica frustules of diatoms and other phytoplankton help make the glass spicules of sponges!

DiatomsSponge

Sponges are boring!

• A family of sponges known as boring sponges bore into shells by use of an enzyme produced by the amebocytes

• Sponge larvae settle onto wood and/or shells and create burrows where they will grow

Sponge worthy?

• Unlike most animals, many sponges reproduce asexually

• Branches or buds break off to form separate, but identical, sponges

• Like all animals, however, sponges also reproduce sexually– Specialized coanocytes or amebocytes produce

eggs and sperm– Sponge larvae is planktonic!

Phylum Cnidaria

• Cnidarians (phylum Cnidaria) are multi-cellular animals with tissues that perform specific functions

• Cnidarians include the sea anemones, jellyfish, coral, and their relatives

• Cnidarians have radial symmetry; in fact radial symmetry evolved in the Cnidarians!

Cnidarians are rad!

• Animals with radial symmetry look the same from all sides and have no head, front or back

• Instead have an oral surface (where mouth is) and aboral surface

Phylum Cnidaria

• Cnidarians have a centrally-located mouth surrounded by tentacles, slender, finger-like projections used to capture and handle food

• All possess stinging cells, or nematocysts• Nematocysts employ neurotoxins which

paralyze prey; 7-17 different types• The mouth opens up to a gut, with only one

opening

Nematocystshttp://www.youtube.com/watch?v=BpKKGB-

ivQo&feature=related

Phylum Cnidaria

• Cnidarians occur in two basic forms: a polyp, a sac-like attached form with its mouth and tentacles pointed upward, and a bell-like medusa, which resembles an upside-down polyp adapted to swimming

• Some Cnidarians have both polyp and medusa stages; others spend their entire lives as either a polyp or a medusa

Phylum Cnidaria, Class Hydrozoa

• The Hydrozoans are a class of very small, predatory Cnidarians which can be solitary or colonial in form

Class Hydrozoa, Order Siphonophora

• Within class Hydrozoa, lies the Order Siphonophora, the Siphonphores– Siphonophores consist of colonies of medusa-like

and polyp-like individuals, each specialized for a specific function

– Specialized features include a gas-filled float, tentacles lined with nematocysts, and digestive cells

– Very toxic!

Portuguese Man o’ War: a siphonophore

By-the-wind Sailors: a siphonophore

Physophora: my nemesis!

http://life.bio.sunysb.edu/marinebio/plankton.html

Actual size

Phylum Cnidaria, Class Scyphozoa

• The Scyphozoans (class Scyphozoa) include most of the common medusa-like ‘jellyfish’

• Larger than Hydrozoans• Short polyp stage; Long medusa-stage

NOAA

Phylum Cnidaria, Class Scyphozoa

• Scyphozoan polyps are very small and release juvenile medusa

• Adult medusa have a rounded body, or bell• Scyphozoans swim with rhythmic

contractions of their bell, but their swimming ability is limited– Planktonic!– Painful stings to swimmers

Phylum Cnidaria, Class Anthozoa

• The Anthozoans (class Anthozoa) include the corals, sea anemones, and sea fans

• Anthozoans lack a medusa stage and exist as solitary or colonial polyps

• Many corals excrete a skeleton of calcium carbonate, which forms reefs (‘reef-building corals’); very important for marine ecosystem

• Anthozoans can sting and ‘attack’ each other!

Class Anthozoa

http://webs.lander.edu/rsfox/invertebrates/aiptasia.html

Phylum Ctenophora

• The comb jellies, or ctenophores are exclusively-marine

• NO nematocysts (not Cnidarians); instead of stinging cells, ctenophores possess sticky cells, or colloblasts

• 8 rows of cilia; Ctenophore literally means “comb bearer”

• ‘Boom and bust’ population dynamics

Phylum Ctenophora

• Most species are bioluminescent• Voracious feeders on copepods, fish eggs,

crab larvae, shrimp larvae and other meroplankton

• Self-fertilizing hermaphrodites• Can double in size in 1 day!• Important secondary consumers

in Long Island estuaries

Peanut butter and jellyfish anyone?

• Ctenophores are increasing in LI estuaries

• During peak ctenophore abundance in Great South Bay (in 2006), one 2-minute plankton tow yielded over 3,700 individuals (543.1 individuals m-3)!

Ctenophores vs. Zooplankton 2009

Ctenophores on Long Island

Spring: Sea gooseberry Summer: Sea walnut Fall: Beroe ovata

Understanding my ctenophore research through Pac Man…

Bivalve larvae(ctenophore food)

Phytoplankton (clam food)

Ctenophore

Lots of ctenophores!!!

GAME OVER(for the hard clam)