Marine Biology Exam 1 Vocab

Phylogeny

evolutionary history of a group of organisms showing how different species are related

Taxonomy

science of classifying, naming, and describing organisms

Taxa

taxonomic group of any ranking

Phyla

taxonomic group above class and below kingdom

Class

taxonomic group below phyla and above order

Monophyletic

group of organisms that includes a common ancestor and all of its descendants

Paraphyletic

a group of organisms that includes a common ancestor but not all of its descendants

Polyphyletic

a group of organisms that do not share a recent common ancestor and have evolved similar traits independently

Outgroup

a species not part of a group (the ingroup) that diverged earlier

Derived group

a group with at least one derived trait which evolved since the common ancestor

Synapomorphy

shared derived characteristic that originated in a common ancestor and is present in all of the ancestor’s descendants but not in more distant relatives

Suspension feeding

feeding on particles suspended in water

Porifera

phyla of metazoa, sessile suspension feeding animals (sponge), perforated bag lined with flagellated cells, aquiferous system

Choanocyte

the cells that make up the choanoderm (inner layer) of sponges, have flagella which allow them to regulate water current through the sponge, have body and microvilli collar which helps catch nutrients to be absorbed into the body

Mesohyl

middle nonliving layer of sponges, made up of the skeleton, spicules and spongin

Ostium

pores in the outer layer that can regulate flow of water

Porocytes

cells that make up the ostia, long tube shaped, crossing all 3 tissue layers

Pinacoderm

outer layer of tissue, made up of pinacocytes (uncilliated, no flagella, thin protection)

Choanoderm

inner layer, made up of choanocytes

Spongocoel

the central cavity of the sponge

Gastrulation

development of embryos by tissue layering

germ layer

early embryonic layers that develop into diff tissues — relates to diff species synapomorphies

Archaeocytes

mobile cell within the mesohyl that plays a role in digestion, is totipotent (can give rise to any cell type

Spicules

mineralized structures, calcium carbonate or silica, in the mesohyl

Spongin

thin, fibrous collagen, forms matrix in the mesohyl

Amebocyte

mobile cell within the mesohyl that plays a role in digestion, is totipotent (can give rise to any cell type

Phagocytosis

eating by cells, extension of plasma membrane encircles article in pockets at cell surface, pinches off

Pinocytosis

cell drinking, taking in nutrients via drinking liquid

Metazoan

clade of eukaryotes, heterotrophic (eat other things), multicellular eukaryotes that undergo embryogenesis (development of embryos) by tissue layering (gastrulation)

Eukaryote

membrane bound nucleus, membrane bound organelles

Cnidaria

phyla of metazoa, includes jellyfish, corals and anemones

Cnidoblast

can be called cnidocyte, the cell containing the cnida such as the nematocyst, the pocked where the nematocyst is before it is deployed

Polyp

body plan of corals and young jellyfish,

Medusae

body plan of adult jellyfish, same structure as the polyp but upside down

Cnidae

type of cell with harpoon like structure

Cnidocil

the part of the cnidae that triggers the release cued by pressure

Nematocyst

type of cnidae that can be launched and contains venom

operculum

protective flap on stinging cells

Mesoglea

form the hydrostatic skeleton between the epidermis and the gastrodermis

Gastrodermis

inner layer of cnidaria that lines the gastric cavity

Tissue

type of materials/cells making up the organism that perform the same function

radial symmetry

symmetrical in a circle, split any way across both sides are the same

Nonbilaterian

not bilaterally symmetrical, having no symmetrical planes

Diploblast

having 2 cells layers

Mesenchyme

connective tissue in the mesoglea

Skeleton

internal framework

hydrostatic skeleton

supports the muscle to allow for movement, formed by mesoglea

Muscles

fibrous connective tissue that can contract to move an organism

nerve net

controls muscles in cnidarians, no central nervous system

Anthozoa

largest group of cnidaria, polyp stage only, reproduce with budding, can be colonial, some have algal symbionts, includes anemones, corals, sea pens

Hydrozoa

most have polyp and medusa stages, some colonial with differentiate functions, zooids = feeding, medusoids = propulsion and reproduction, include siphonophores and hydroids

Scyphozoa

true jellyfish, medusa and polyp stages, medusa reproduce sexually, polyps clonal

calcium carbonate

makes up skeletons of some corals

Coral

type of anthozoa

Jellyfish

scyphozoa

Anemone

anthozoa

Hydroid

hydrozoa

Siphonophore

colonial organisms

Mollusca

phyla of metazoa, containing bivalves, gastropods, polyplacophora, and cephalopods

Bivalve

class of mollusca including clams, mussels, oysters and scallops

Gastropoda

class of mollusca including snails, abalone, and nudibranchs

Open circulatory system

circulatory system that goes in two directions from pump to gills, allows the blood to flow out of the blood vessels into body cavities so cells are in direct contact with blood

Closed circulatory system

circulatory system that goes in one direction in a cycle, blood cells never leave the blood vessels

Coelom

opening inside the body/body cavity

Mesoderm

middle cell layer

Peritoneum

membrane that lines the abdominal cavity

Dorsal

toward the back

Ventral

toward the stomach

Anterior

toward the head

Posterior

toward the tail

Gonad

female or male reproductive organ that produces sex cells and hormones

Polyplacophora

class of mollusca including chitons, in chitons radula teeth are covered with magnetite made from iron

Nudibranch

type of gastropod

Snail

type of gastropod

Clam

type of bivalve

Whelk

type of gastropod, some use radula on long proboscis to catch prey

Radula

the mouthparts unique to most molluscs, used often to scrape rocks to feed in snails and chitons

Oyster

type of bivalve

Mussel

type of bivalve

Triploblastic

three cell layers

bilateral symmetry

symmetrical across one line of symmetry

Foot

large, well defined muscle, often with flattened sole for attachment or creeping

Periostracum

thin outer organic layer

Gut

space for digestion

Mouth

opening to take in food etc

Anus

opening to release waste

Digestion

breaking down food

Herbivore

eats only plant material

Carnivore

eats other organisms

Ctenidium

gills, for gas exchange, in snails and bivalves

byssal thread

anchoring threads secreted by molluscs

Mantle

cuticle covered epidermal sheet of tissue, secrete calcareous structures (shells)

Epidermis

outer layer of mollusca