The Phylum Ctenophora Ktenos = comb Phoros = bearing

How do Ctenophores differ from Sponges?

Characteristics of Ctenophora 8 rows of combs (cilia) Radially symmetrical Body consists of two layers with a third layer called mesoglea (jelly-like substance)

Characteristics of Ctenophora Body contains an internal cavity and a mouth and anal pores No respiratory or circulatory system; simple diffusion Sexual Reproduction – hermaphrodites All are carnivorous; capture prey with ten

Benthic (bottom dwelling) Ctenophores Order Platyctenida. Found in warm water Branched tentacles Look more like sea slugs Vallicula multiformis

Coastal Ctenophores Order Cydippida – Round or oblong in shape – Usually less than 3 cm (1 inch) in diameter Sea gooseberry Pleurobranchia pileus

Coastal Ctenophores Order Lobata – Largest – Pair of lobes that are used to capture prey – Short tentacles that remain inside the lobes. Common northern comb jelly Bolinopsis infundibulum

Coastal Ctenophores Order Beroida – Flat and grows up to 15cm – Translucent: light pink or yellowish Beroe’s comb jelly

Oceanic Ctenophores Found far off-shore near the surface More fragile than coastal species Wing-like Venus’ girdle Cestum veneris

Tortugas red

Ctenophore life cycle Hermaphroditic, both egg and sperm. Eggs and sperm released and fertilized at sea. Fertilized eggs develop into a larval stage which gradually grows into an adult.

Ctenophore life- scattering/bioluminescence: beating rows of cilia; light defraction Most Ctenophores are bioluminescent. Beroe

How do ctenophores fit into the food web? All ctenophores are carnivores. Sticky tentacles adhere to small zooplankton prey which is to the ctenophore’s mouth.

Ctenophores as marine invaders wreaking ecosystems: Ctenophores are recognized to be planktonic carnivores Leidy’s comb jelly (Mnemiopsis leidyi) was introduced into the Black sea and caused a full ecosystem fisheries collapse within less than 10 years – Why? Outcompeted for plankton Order Lobate

Ctenophores and Medusae (Jellyfish) are they related? No Both are plank tonic, carnivorous, often transparent and tentacle bearing At one time, they were both placed in Phylum Coelenterata but today they are separated. No polyp stage in Ctenophores

How are Phyla Porifera and Ctenophora similar? Different? 2 layers: Endoderm Ectoderm with jelly-like middle called the mesoglea Hermaphrodite No digestive or respiratory system Porifera: Sponges Ctenophora: Comb jellies Asymmetrical symmetry Sessile Filter feeder Regeneration No true tissues or organs Radial symmetry Mobile Carnivorous Cilia Tentacles Bioluminescence Mouth/anal pores