Marine Inverts Exam 1

What are invertebrates?

Animals that lack a backbone

Why are Inverts Important?

• Ecologically important for nutrient cycling, filtration, or habitat.

• Economically important for food, ecotourism (shelling), and pharmaceuticals.

What is taxonomy?

a branch of science concerned with classification, especially of organisms, systematics.

why is taxonomy important?

classify new spieces with other like species, conservation

What is phylogeny?

The study of evolutionary reationships

Phylogenetic systematics

field within biology that reconstructs evolutionary history and studies the patterns of relationships among organisms.

homologous traits

Traits or structures that are similar in two or more species, showing that organisms have descended from a common ancestor

Binary characters

useful for classification because it allows for easy separation of groups by designating presence v. absence or selecting from one of two states, such as long v. short, one antenna v. two antenna, and so on.

Multistate Characters

a character that can occur in several character states

Character state

particular version of a character

Principle of Parsimony

The principle that the most acceptable explanation of an occurrence, phenomenon, or event is the simplest, involving the fewest entities, assumptions, or changes. In phylogenetics, for example, the preferred tree showing evolutionary relationships between species, molecules, or other entities is the one that requires the least amount of evolutionary change, that is, maximum parsimony.

monophyletic

Describes a group of organisms that are classified in the same taxon and share a most recent common ancestor, traits are shared and derived (synapomorphy).

Paraphyletic

A group that contains a common ancestor and some, but not all, of the decendants. Implying that some members of the natural group have been places into another group.

Polyphyletic

A group of that is of mixed evolutionary origin, but share similiar features (homoplasies)

Bilateral symmetry

Left and right vertical → helps with a head (humans)

Radial symmetry

Cut any direction, symmetrical(cnidarians, ecginoderms (pentaradial))

Asymmetrical

no symmetry (sponges)

Diploblastic

2 tissue layers (endoderm & ectoderm)

Triploblastic

3 tissue layers (endoderm, ectoderm, & mesoderm)

Coelom

body cavity found in metazoans that surrounds and contains th digestive trat and other organs

significance of a coelom

relates to potential for increased body size

Protostome

Mouth developes from blastopore

Deuterostome

Anus developes from blastopore

metazoan

animals that are multicellular, and have cells differentited into tissue and organs, using sspecialized cells.

Choanocytes

fagellated cells that drive water through canals and chambers constituting the aquiferous system

pluripotency

function as stem cells

epithellial cells

surface cells that act as a “skin”, in sponges cells are connected but dont share materials through adheran junctions, but lack gap junctions

asconoid

• simpliest sponge body form

• ostia

• choanocyte in spongocoel

• osculum

syconoid

• ostia

• choanocyte in radial canal

• apopyle

• spongocoel

• osculum a

leuconoid

• complex ostia

• incurrent canal

• choanocyte in radial canal

• excurrent canal oscula

spicules

skeletal elements that are composed of calcium carbonate, or silicon oxide

megascleres

large spicules

microscleres

small spicules

Spongin

a fiborous materal that forms part of the sponges skeletal system

Importance of sponges

• primary producers

• filtration

• habit

Parasitic behavior of Cliona

common bioeroder

Osculum

large aperture in a sponge through which water is expelled

spongocoel

the large open cavity of sponges

mesohyl (mesoglea)

the gelatinous matrix within a sponge, incuding motile cells and some skeletal material

porocyte

allows water into the sponge through its opening (ostium)

pinacocytes

thin layer that keeps water out of the sponge

cnidae

gereal term for specialized cells for example nematocysts

endoderm

inner tissue layer

ectoderm

outer tissue layer

myoepithelial cells

epitheliomuscular cells and nutitive cells derived from endoderm and ectoderm to form musculature

epidermis

outmost body layer

mesoglea

an extracellular matrix that lays between the epidermis and the gastrodermis in cnidarians that functions as a hydrostatic skeleton. Acellular.

siphonoglyph

a ciliated groove at one or both ends of the mouth of sea anemones and some corals.The siphonoglyph extends into a pharynx and is used to create currents of water into the pharynx

gastrodermis

the inner layer that serves as a lining memberane of the gastrovascular cavity (coelenteron) in cnidarians

gastrovascular cavity (coelenteron)

sac-like , partioned or branched, but with a single opening serving as both mouth and anus (cnidarians)

colloblast

multicellular structures found in ctenophores, they consist of collocyte lining and can be dischaged from the animals tentacles and used to capture prey. Not stinging cells but sticky to catch prey.

mesochyme

similiar to mesogela but has cells

velum

a membrane part that resembles a veil or curtain

ctene

a locomotor organ consisting of a row of strong cilia whose bases are fused (Ctenophores)

gonochoristic

a sexual system in which there are only two sexes and each individual is either male or female

hermaphroditic

an individual that possesses both male and female reproductive organs, structures, or tissues

soft corals (octocorals)

tentacles (cnidae) in multiples of 8

hard corals (hexacorals)

tentacles (cnidae) in multiples of 6

Rhopalia

small sensory structures that generally occur in multiples of four in cnidarieans (scyphozoan, and Cubozoan)

reproduction in corals

1. Gamete bundles released
2. bundles disassociate
3. fertilization
4. clevage → 4-cell → 8-cell
5. monrula
6. different shape stages
7. elongated planulae
8. searching
9. settlement
10. budding
11. Adult
12. repeat

importance of cnidaria

• primary producers

• habitat

• source of food

Common features of all worms

• cephalization

• central nervous system (CNS)

• bilateral symmetry

• triploblastic

Protonephridia

a type of nephridia that are network of dead-end tubules without internal openings

metanephidia

a type of nephridia that are a type of eccretory glands with a ciliated funnel opening into the body cavity

Surface area to volume ratio

higher SA:V ratio allows for a more efficient diffusive processes than a low SA:V ratio

Pharynx

“throat”: smooth part following the mouth

Proboscis

an extensible tubular sucking organ

Rhynchocoel

coelomic hydrostatic chamber (Nemertea)

Renette cells

Specialized excretory cell in nematode worms

Metamerism

the repetition of homologous body segments

Segmentation

the division of some animal body into a series of repetitive segments

teloblastic growth

a large cell in the embryos of clitellate annelids which asymmertrically divide to form many smaller cells known as blast cells which further proliferate and diffeentiate to form the segmental tissues of the annelid

Open circulatory system

blood suffuse the body and may be directly open to the environment at places such as the digestive tract. has a hemocoel that is a central body cavity that may have some arteries but are not closed

closed circulatory system

blood stays within blood vessels, this way blood is kept separate from body tissues, this system has a heart that pumps blood through a continuous circulation pattern

trocophore larvae

a type of free-swimming plantonic marine larva with several bands of cilia

blastocoelic

a fluid filled or yolk filled cavity that forms in the blastula during early embryonic developemt

ganglion (ganglia)

dense group of nerve- cell bodies present in most animals above the level of snidarians

diverticulae

\*if viewing a cross section

the lining of the whit spaces