Zoology Exam 3

Annelids

Segmentation

Division of the body into discrete segments or metameres, serially repeated units, each unit has components of most organ systems.

Phylum Annelida

Phylum consists of segmented worms and non-segmented worms whose ancestors exhibited segmentation

Coelomate

When an organism has a coelom.

Lophotrochozoan protostome

Any member of a clade within Protostomia whose members generally either possess a trochophore larva or a lophophore

Trochophore

Free-swimming ciliated marine larva characteristic of most molluscs and certain ectoprocts, branchiopods, and marine worms; ovoid or pyriform body with preoral circlet of cilia and sometimes a secondary circlet behind the mouth.

Annuli

circular grooves that are externally present in segments of annelids

Septa

the internal division of segments in annelids via membranes between each segment

Setae

The tiny chitinous bristles that annelids usually have, used in locomotion or anchorage

Short setae

structures present on segments of annelids used for anchorage

Long setae

structures present on segments of annelids used for swimming

Prostomium

The anterior-most (front) part of annelid heads

Peristomium

The part of annelids head that is posterior-most (back)

Pygidium

The posterior (ending) part of a segmented organism, bears the anus. Metameres (segments) form in front of this structure

Thin non-chitenous cuticle

The body covering of annelids

Hydrostatic Skeleton

Coelom filled with pressurized fluid in annelids (except leeches), maintains a constant volume

Circular and longitudinal muscles

used to contract and squeeze fluid of hydrostatic skeleton to move, these work in alternating contractions with each other

Clade Errantia

The freely moving, mostly marine polychaete clade of annelids. Large group, 1mm-3m long, parapodia on most segments, many setae in bundles on parapodia, mostly predators or scavengers

Clade Sedentaria

The sedentary clade of annelids, include polychaete, oligochaete, and leeches. Includes subgroup clitella, live in tubes/burrows, may have gills to supplement respiration, and tentacles on head capture food and respire. .

Polychaetes

old annelid class where members had many setae and parapodia

Parapodia

flap-like appendages on segments of annelids

Oligochaetes

old class of annelida that have no parapodia, few setae, and a clitellum

Clitellum

an area of the body in annelids with specialized cells that form a protective mucus layer during reproduction for the cocoon stage.

Annelids that do not fall under main clades.

Chaetopteridae (parchment worms) and Sipuncula (peanut worms)

Clade Errantia form

these annelids have prostomium (eyes, tentacles, sensory palps), peristomium (setae, palps, chitenous jaws), most trunk segments have parapodia (usually main respiratory organ, body surface can be used for gas exchange and some have gills)

Clade Errantia Function

these annelids have a complete gut, highly developed sense organs (eyes can vary from simple eyespots to image-forming), and most have metanephridia for excretion

Metanephridium

Excretory system that each segment has with a small external tube from coelom to out of the organisms body wall

Clade Errantia Reproduction

these annelids are usually dioecious, have no permanent sex organs (gonads temporarily appear to save energy and gamtes are shed into the coelom and exit body this way), and external fertilization (released into water)

Clade Errantia Swarming Sexual Stages

these annelids mostly live as sexually immature, during this period the posterior becomes sexually mature and breaks off, these parts then swim to the surface and burst for fertilization

Atoke

sexually immature errantia annelids

Epitoke

the posterior end of errantia annelids that breaks off for reproduction

Clam Worms

predatory errant polychaetes that hide in burrows and have chitenous jaws on their eversible muscular pharynx

Scale Worms

this annelid has flattened bodies covered with broad scales, some can get up to 20cm, and all are carnivores

Fireworms

These annelids have hollow, brittle setae that contain neurotoxins, and they feed on cnidarians

Tubeworms

these annelids are polychaetes that have flexible or rigid tubes, they are usually particle feeders that consume either suspended particles or particles in/on sediments

Fanworms

these annelids are tubeworms, they unfurl tentacular crowns to feed, food is moved from radioles to mouth by ciliary action, it includes feather duster worms and christmas tree worms

Siboglinids (Beardworms)

these annelids are mostly in sea floor mud at 100-10,000 deep, theyre sessile and secrete, they live in long chitinous tubes

Beardworm Adaptations

these annelids have adapted to have no mouth or digestive tract, absorb some nutrients from seawater through tentacles, they get most of their energy from mutualistic chemoautrophic bacteria that oxidize hydrogen sulfide

Ciliary Feeders

annelids that eat suspended articles

Deposit Feeders

annelids that eat particles on/in sediments

Radioles

feather-like processes from the head of many tubicolous polychaete worms used primarily for feeding

Mutualistic Chemoautrophic Bacteria

Organisms that oxidize hydrogen sulfide in a relationship with another organism and provide energy

Siboglinids - Osedax

Worms that eat whale corpses, symbiotic bacteria help digest fats and oils inside whale bone

Clade Clitellata

the annelids that include earthworms, leeches, have reproductive structure called clitellum, monoecious with direct development, no parapodia

Clitellum

a reproductive structure that is a ring of cells around the body that secrete cocoons

Direct Development

When an organism has no larval stage

Indirect Development

When an organism has a larval stage

Oligochaete Diversity

these annelids live in soil and freshwater habitats, most have setae (less than polychaetes)

Earthworm Form

the form of these annelids live in branching tunnels and often emerge at night, in dry weather they burrow deep underground, they alternate circular/longitudina muscle contractions to move, setae help anchor their segments.

Earthworm diet

the diet of these annelids consists of being scavengers, they feed on decayed organic matter/leaves (temporarily stored in crop and ground into small pieces in gizzard), ingest own weight in soil every 24 hours, important to mixing/aeration of soil

Earthworm function

these annelids function by using cutaneous respiration, metanephridia in most segments, simple sense organs in body (no eyes but photoreceptors in epidermis, chemoreceptors, and respond to mechanical stimuli)

Crop

the organ where earthworms temporarily store their food after swallowing, before ‘chewed up’

Gizzard

the muscular area that contracts to ground soil into small pieces for digestion

Cutaneous Respiration

When earthworms use body surface for gas exchange

Earthworm reproduction

These annelids are monoecious, align in opposite directions (held with mucus from clitellum), exchange sperm, each forms cocoon where fertilization occurs

True Leeches

one order only, hirudinea, have no setae or parapodia, 2 suckers (one on anterior and posterior end)

Non-True Leeches

two orders, these annelids have fewer segments and only 1 sucker

True Leech Features

these annelids are mostly freshwater, tropical, lack internal septae, some are carnivores, feed on small invertebrates, others are temporary or permanent parasites (secrete anesthetic and anticoagulant)

Anticoagulant

a compound that keeps blood flowing and is a blood thinner

True Leech Adaptations

these anelids have a specialized gut to store large quantities of blood, used medically to reduce blood clotting and encourage reattached limb healing

Enterocoely

The process of how the coelom evolves in deuterostomes

Schizocoely

The process of how the coleom evolves in protostomes

In what groups did metasterism evolve in?

This trait evolved in deuterostomes, lophotrochozoans, and ecdysozoans

cuticle

a non living outerlayer secreted by the epidermis

Ecdysis

the process of shedding off the outer cuticular layer; molting

Phylum Nematoda

this phylum consists of the roundworms, they are found almost everywhere and parasites exist in nearly all animal and plant species

Nematoda Diet and Importance

the free living worms eat a variety of foods (bacteria, yeast, algae, some saprozoic and some coprozoic), many organisms eat these worms, and C. elegans is an important model for genomic studies

Saprozoic

a method of eating where an organism feeds by absorption of dissolved salts and simple organic nutrients from surrounding medium; also refers to feeding on decaying matter

Coprozoic

a method of nutrition where an organism gets its nutrients by consuming feces

Nematoda form

these worms have a cylindrical shape, nonliving cuticle, only longitudinal muscles in the body wall, and are eutely

Eutely

when a species has a set amount of cells

Nematodes Muscle and Movement

in these worms the cuticle acts antagonistically to the longitudal muscles (produces thrashing motion), hydrostatic skeleton helps provide support (higher pressure→higher effeciency)

Nematoda Metabolism

these worms have anaerobic metabolism (some parasitic adults and use glycolysis and other ET processes), aerobic metabolism (free living nematodes and free living parasitic stages)

Nematoda Reproduction

in these worms most are dioecious, the males have copulatory spicules, internal fertilization, unique sperm with no flagella (move via ameboid movement, adaptation to hydrostatic pressure?)

Copulatory Spicules

Spikes that help inject sperm into the female worm

How many people in the world are infected with ascaris

~1 billion

Ascaris Life Cycle

Host swallows embryonated egg→juveniles hatch, burrow through intestinal wall→juveniles travel to lungs, carried up to trachea→coughed up, swallowed, mature in intestine→feed on intestinal contents - may block or perforate intestines

How can hookworms cause issues in humans?

Ingest more blood than needed and can cause anemia in host, burrow thru skin into blood

Trichinosis

caused by Trichina Worm, make host cells become nurse cells

Nurse Cell

a cell whose gene expression has ben redirected to cater only to a parasite

Pinworms

most common nematode parasite in the U.S. (30% of kids)

Filarial Worms

8 species of these nematodes can infect humans, Wuchereria bancrofti and Brugia malayi live in the lymphatic system

Filarial Elphantiasis

caused by repeated exposure to Wuchereria or Brugia infection, an excessive growth of connective tissue and enormouse swelling of affected parts

Phylum Arthropoda

Most diverse phylum, coelomate protostomes, well-developed sense organ systems, mostly herbivorous, segmented

Arthropod subphyla

Trilobita, Myriapoda, Chelicerata, Crustacea, and Hexapoda

Subphylum Trilobita

an extinct subphylum of phylum arthropoda.

Subphylum Myriapoda

the subphylum in arthropoda that includes centipedes, millipedes, etc.

Subphylum Chelicerata

the subphylum in arthropoda that includes spiders, ticks, horseshoe crabs, scorpions, etc.

Subphylum Crustacea

The subphylum in arthropoda that includes lobsters, crabs, crayfish, etc.

Subphylum Hexapoda

the subphylum in arthropoda that includes insects

Reason that arthropods have great diversity and abundance

versatile exoskeleton, cuticle, molting, tagmata

Hemocoel

a blood filled reduced coelom that arthropods use for respiration with an efficient tracheal system, residual blastocoel

Arthropod locomotion

organisms in this phylum exhibit segmentation and appendages to have efficient locomotion. they often have highly specialized appendages

Tagmata

segments that are fused into specialized groups in arthropods

Arthropod Respiration

terrestrial organisms have efficient tracheal system. for O2 transport (air piped directly to cells and supports their high metabolic rate), aquatic organisms have gills

Tracheal System

set of tubes that run through an arthropod’s body used for respiration

Arthropod Senses

these organisms have a variety of highly developed sense organs, including compound (mosaic) eyes, touch, smell, hearing, balancing, and chemical reception

Arthropod behavior and metamorphosis

these organisms have more complex and organized activities than other invertebrates, most behavior innate, some learned. having larvae gets rid of competition for food and habitat, as adults usually have different diet and habitat

Interspecific Competition

Competition within species

Interspecific Species

Competition between species

Characteristics of subphylum trilobita

flourished during the cambrian period, extinct 245 mya, tri-lobed body shape, bottom dwellers (probably scavengers), three tagmata