Term
A. Metamerism
1. Metamere/Somite |
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Definition
A. Segmental arrangement of body parts in an animal
1. each segment of a worm |
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Definition
| grooves found externally BETWEEN each somite |
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Term
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Definition
Internal membranes formed from adjacent peritoneum of segments
-form internal division membranes |
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Term
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Definition
| the specialization of body regions in a metameric animal. |
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Term
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Definition
tiny chitinous hairs that ANCHOR the annelid during locomotion to prevent backward slipping
- can be used for swimming as well in some
- bristles secreted from invaginations of the distal ends of parapodia. |
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Term
| Tagmatization - Class Polychaeta |
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Definition
| have a well-developed head with specialized sense organs, PARAPODIA and NO clitellum. |
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Term
| Parapodia - Class Polychaeta |
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Definition
paired appendages
- numerous setae project from the parapodia, giving them their class name.
- used in locomotion and respiration |
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Term
| Prostomium - Class Polychaeta |
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Definition
a lobe tat projects dorsally and anteriorly to the mouth.
- contains sensory structures such as the eyes, antennae, sensory palps, and tentacle. |
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Term
| Pygidium - Class Polychaeta |
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Definition
the terminal portion of the worm where the anus is found
- not considered a somite. |
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Term
| Peristomium - Class Polychaeta |
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Definition
the 1st segment of the worm
- surrounds the mouth
- may bear cirri |
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Term
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Definition
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Term
| Epidermis - Class Polychaeta |
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Definition
| a single layer of columnar epitelial cells that secrete a non-living cuticle |
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Term
| Cuticle - Class Polychaeta |
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Definition
a protective secretion by the epidermis
- may contain luminescent compounds. |
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Term
| Longitudinal Muscles - Class Polychaeta |
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Definition
| muscles on each sides of the body that allow movement in polychaetes |
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Term
| Digestive tract - Class Polychaeta |
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Definition
A straight tube suspended in the coelom by the mesentaries and septa.
- consists of a pharynx, probiscus, crop, grinding gizzard & long intestine
*Predatory - probiscus and poison glands
*Herbivores/scavengers - jaws to tear
*Deposit-feeders - organic matter they ingest
*Filter feeders - no probiscus, replced by radioles |
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Term
| Radioles - Class Polychaeta |
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Definition
| feathery arms that contain cilia that trap food particle in mucous that is carried/ |
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Term
| Casting - Class Polychaeta |
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Definition
| what organic matter is known as after it's digested, passed through the intestine and is released... |
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Term
| Gas exchange - Class Polychaeta |
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Definition
| By DIFFUSION through the body wall and parapodia. |
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Term
| Closed Circulatory System - Class Polychaeta |
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Definition
Oxygen carried in respiratory pigments instead of blood.
- may make the blood colorless, green or red
- contractile elements consist of a DORSAL vessel on dorsal side of the digestive tract that pumps blood ANTERIORLY and a VENTRAL vessel that pumps blood POSTERIORLY |
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Term
| Extra Info- Class Polychaeta |
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Definition
Polychaetes that live in rich organic substances can absorb as much as 40% of their energy requirements through the body wall
- occurs in other animals but usually only to the extent of 1% |
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Term
Nervous System - Class Polychaeta
(Each segment acts separately from, but is closely coordinated with, neighboring segments...) |
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Definition
Consists of a pair of suprapharyngeal ganglia ("brain")which connect to a pair of subpharyngeal ganglia by circumpharyngeal connectives that run dorsoventrally along either side of the pharynx.
A double, ventral nerve cord runs from the subpharyngeal ganglia the length of the worm. |
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Term
| Nervous System (cont.) - Class Polychaeta |
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Definition
Segmental ganglia - coordinate swimming and crawling movements in isolated segments.
Lateral nerves emerge from each segmental ganglion.
- supplies the body wall musculature & other structures of that segment.
Sensory structures in the head - 2-4 eyes on the surface of the prostomium.
- simple to complex w/cornea, lens, & vitreous humor. |
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Term
| Nuchal organs - Class Polychaeta |
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Definition
| a pair of ciliated sensory pits in the head region acting as CHEMORECEPTORS for food detection |
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Term
| Statocysts - Class Polychaeta |
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Definition
| located on head region for equilibrium and balance |
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Term
| Tactile Receptors - Class Polychaeta |
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Definition
| ciliated tubercles, ridges and bands that cover the body wall |
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Term
| Nephridia - Class Polychaeta |
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Definition
| accomplish the excretion of nitrogenous wastes and help maintain the osmotic balance |
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Term
| Protonephridia - Class Polychaeta |
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Definition
| bulbular end projecting through the anterior wall of the adjoining segment and the opposite end opening on the segment to the outside through a nephridiopore |
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Term
| Nephridiopore - Class Polychaeta |
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Definition
| an opening on the nephridia |
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Term
| Metanephridium - Class Polychaeta |
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Definition
Consists of a nephrostome that projects through an anterior septum into the coelom of an adjacent segment.
At the other end in the segment containing extensively coiled tubules, with a portion dilated into a bladder, it opens to the outside through a nephridiopore.
(Most common type of nephridia in polychaetes) |
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Term
| Nephrostome - Class Polychaeta |
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Definition
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Term
| Regeneration - Class Polychaeta |
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Definition
they can replace lost parts, and some species have break points that allow worms to sever themselves when a predator grabs them.
- lost segments are later regenerated... |
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Term
| Reproduction - Class Polychaeta |
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Definition
MOST ARE DIOECIOUS
-some reproduce asexually through budding or transverse fission.
- fertilization is external
- trochophore larva bud segments anterior to the anus
- Larva settles to the substrate and adds newer segments posteriorly
- ANTERIOR END OF THE WORM IS THE OLDEST.
- MANY POLYCHAETES LACK A LARVAL STAGE AND HAVE DIRECT DEVELOPMENT. |
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Term
| Epitoky - Class Polychaeta |
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Definition
| the formation of a reproductive individual (EPITOKE) that differs from the nonreproductive form of the species (an ATOKE) |
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Term
| Epitoke - Class Polychaeta |
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Definition
Frequently has a body that is modified into 2 body regions.
- Anterior are normal where the posterior segments are enlarged and filled with with gametes.
- also may have modified parapodia for more efficient swimming.
All gametes are released at a certain time of the year and fertilized eggs develop into trochophore larva and develop into nonreproductive adults... |
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Term
| Class Clitellata - overview |
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Definition
-includes the earthworms and leeches
-put into same class because of the presence of a clitellum
-monoecious
-presence of few to no setae
-Subclass Oligochaeta - Earth Worms
-Subclass Hirudinea - Leeches
- BOTH LACK PARAODIA |
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Term
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Definition
| cocoon-secreting structure |
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Term
| Subclass Oligochaeta - overview |
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Definition
-MOST ARE TERRESTRIAL but many live in freshwater.
-some are MARINE or are found in estuaries
-have setae, but aren't as numerous as the polychaetes.
-OLIGOCHAETA mean "few long hairs"
-MOST FAMILIAR >>> the Earthworm or "Lumbricus terrestris"
-LACK PARAPODIA!!!! |
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Term
| Earthworm scientific name |
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Definition
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Term
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Definition
| a small lobe in the front of the mouth that lacks sensory appendages. |
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Term
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Definition
| Usually somites 32-37, swollen into a girdle-like structure that secretes mucous during copulation and forms the cocoon. |
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Term
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Definition
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Term
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Definition
| a nonliving cuticle secreted by the epidermis covers the body. |
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Term
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Definition
Involves the antagonism of circular and longitudinal muscles.
-when longitudinal muscles contract, the segment swells and setae are protruded
-the previous segment contracts its circular muscles causing the retraction of the setae, pushing forward the anterior segment.
-SEGMENTS MOVE FORWARD AS WAVES OF MUSCULAR CONTRACTIONS MOVE ANTERIORLY |
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Term
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Definition
| found to the exterior beneath the epidermis |
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Term
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Definition
| found to the interior of the circular muscles. |
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Term
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Definition
| found anterior to the longitudinal muscles and lining the coelom |
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Term
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Definition
4 pairs are found on most segments
-two ventrally
-two ventrolaterally that aid in locomotion. |
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Term
| Oligochaetes are SCAVENGERS |
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Definition
| Feed primarily on decaying vegetation (detritus) |
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Term
| Digestive Tract - Oligochaeta |
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Definition
| Food pulled in by Pharynx > Mouth > Esophagus(calciferous glands) > Crop > Muscular Gizzard > Intestine > Anus(and out a nephridiophore) |
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Term
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Definition
| pulls food into the mouth and then pushes it down the esophagus. |
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Term
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Definition
| evaginations of the wall of the esophagus that rid the body of excess calcium absorbed from food |
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Term
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Definition
| thin-walled food storage structure |
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Term
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Definition
| used for grinding the food |
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Term
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Definition
a straight tube where digestion and absorption occurs.
-ends at the Anus. |
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Term
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Definition
| a dorsal unfolding of the intestinal wall that functions in increasing the surface area of the intestine. |
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Term
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Definition
SOMITES 7-11
- expanded segmental vessels referred to as "hearts"
- up to FIVE PAIRS of hearts.
- Main propulsion of the blood is still done by the dorsal and ventral vessels. |
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Term
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Definition
Ventral Nerve Cord & all ganglia have undergone a high degree of fission.
- giant fibers control escape response and small diameter fibers are for locomotion and coordination.
-LACK well-developed eyes and have receptors scattered all over the body surface, especially around the prostomium for MECHANICAL and CHEMICAL reception. |
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Term
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Definition
the excretory structures
- the funnels of the metanephridia are found in the segment ANTERIOR to the segment containing the tubules and nephridiopore |
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Term
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Definition
surrounds the dorsal vessel and over the dorsal surface of the intestine.
**The site of AMINO ACID METABOLISM deaminating amino acids and converting ammonia to urea
- also converts carbs into glycogen and fats |
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Term
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Definition
| Deamination is the process by which amino acids are broken down if there is an excess of protein intake. The amino group is removed from the amino acid and converted to ammonia. The rest of the amino acid is made up of mostly carbon and hydrogen, and is recycled or oxidized for energy. |
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Term
| ALL Oligochaetes - MONOECIOUS |
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Definition
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Term
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Definition
| (of a plant or invertebrate animal) having both the male and female reproductive organs in the same individual; hermaphrodite. |
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Term
| Cross-Fertilization (fyi) |
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Definition
| Fusion of male and female sex cells from different individuals of the same species. Cross-fertilization is necessary in animal and plant species that have male and female organs on separate individuals. |
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Term
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Definition
associated with the seminal vesicles.
- SPERM released through the sperm duct openings on the ventral side of SOMITE 15 |
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Term
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Definition
produced in the ovaries on SOMITE 13
- RELEASED through the oviduct openings on SOMITE 14
- hatch in 1-2 weeks |
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Term
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Definition
In the grooves between SOMITE 9-10 and 10-11..
- RECEIVE SPERM during copulation. |
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Term
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Definition
| Sites for maturation and storage of sperm PRIOR to their release. |
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Term
REPRODUCTION OF EARTHWORMS
(Lumbricus terrestris) |
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Definition
1. Sperm is transferred to the seminal receptacles of each worm.
2. Following coopulation, CLITTELUM forms a cocoon for the deposition of eggs and sperm
-cliittelum secretes a food reserve, albumin, into the cocoon
3. Eggs are deposited into the cocoon through oviduct openings (SOMITE 14)
4. Sperm is released as the cocoon passes over the seminal receptacle openings on (SOMITE 9-11)
5. eggs are fertilized in the cocoon and as the worm continues to back out it deposits the cocoon of fertilized eggs in the soil.
6. Eggs hatch in 1-2 weeks into young worms (NO LARVAL STAGE)that emerge from the cocoon. |
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Term
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Definition
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Term
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Definition
- MOST are FRESHWATER, but some are marine and some are completely terrestrial, living in warm, wet places.
- more abundant in tropical countries than temperate zones |
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Term
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Definition
May be Carniverous or Parasitic
- prey on small invertebrates
- feeding on bodily fluids of vertebrates, sometimes blood
- NOT TRULY PARASITIC because the leech is only on the host for a short amount of time.
- Not species specific, but class specific...
>>>> PREDATORY!!! would be the best term for leeches
- The MOUTH opens in the middle of the anterior sucker on (SOMITE 1)
- may have protrusible proboscis or 3 chitinous jaws
- Secretes Hirudin, an anticoagulent, into the tissue of the host to prevent clotting.
- PHARYNX pumps body fluid from host into esophagus that leads to the stomach with lateral cecae.
- Digestive tract end in a short and anus.
- A leech may go months without food after a feeding. |
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Term
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Definition
- DORSOVENTRAL
- adapted for forcing their proboscis into soft tissue
- some have chitinous teeth that can cut through skin |
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Term
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Definition
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Term
| Reproduction of leeches - Sexual |
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Definition
MONOECIOUS w/ a clittelum that only appears during the breeding season.
- Single pair of overies and 4+ testes
- Clitellum on 3 segments in the spring when they breed.
- sperm transferred by penis or by hypodermic injection of spermatophores through the tegment of the other.
- cocoons deposited into soil or attached to underwater objects.
- NO LARVAL STAGE, offspring mature by the following spring. |
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Term
| Monoecious (fyi) and Reproduce Sexually |
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Definition
| (of a plant or invertebrate animal) having both the male and female reproductive organs in the same individual; hermaphrodite. |
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Term
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Definition
EXACTLY 34!!!!
- difficult to extinguish externally |
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Term
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Definition
| reduced or lacking; ABSENT IN MOST |
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Term
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Definition
at both ends of their bodies
- anterior and posterior |
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Term
| LACK PARAPODIA AND HEAD APPENDAGES |
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Definition
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Term
Annuli (plural)
- annulus (sing.) |
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Definition
| transverse grooves that each segment is marked with externally that give the appearance of secondary divisions in the somite. |
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Term
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Definition
Make Leeches' muscular system more complex than other annelids.
- located between the circular and longitudinal muscles |
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Term
Hydrostatic cavity
(locomotion) |
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Definition
used in a looping type of locomotion since the septa are lost.
- connective tissue has invaded the coelom.
- can also swim by undulating their bodies.. |
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Term
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Definition
| a blind tube leading from a cavity or passage. |
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Term
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Definition
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Term
| Highly Modified Coelomic Sinuses (MOST) |
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Definition
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Term
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Definition
| has taken over the function of the blood and respiratory pigments are lacking. |
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Term
| Nervous System - Nerve Ring |
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Definition
has fused the suprapharyngeal ganglia, circumpharyngeal connectives, and subpharyngeal ganglia into a nerve ring around the pharynx (mouth)
- ventral nerve cords are unfused other than at the segmental ganglia.
- posterior ganglia also form a nerve ring. |
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Term
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Definition
10-17 pairs of metanepridia...
- one per segment in the middle segments of the leech |
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Term
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Definition
| found throughout the coelomic cavity |
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