Excersice 39 Arthropods

BIO 104S

Common names of the Phylum Arthropods

spiders, scorpions, crayfish, insects

A contributing factor to Arthropods being the most successful animal phylum

jointed appendages

Common names of the Phylum Arthropods

spiders, scorpions, crayfish, insects

A contributing factor to Arthropods being the most successful animal phylum

jointed appendages

jointed appendages/ paired appendages

Extensions of the main body and highly adapted for locomotion, reproduction, feeding, defense, and sensing the environment.

What is their exoskeleton made of?

chitin

How does chitin in the exoskeleton benefit?

It provides protection, a moisture barrier, and a place for muscle attachment.

Chitin is a primary component of the exoskeleton

It is structurally similar to cellulose and functionally similar to keratin.

In insect exoskeletons, chitin is combined with what else?

sclerotin

In crustaceans’ exoskeletons, chitin is combined with what else?

calcium carbonate

Around how many Arthropod species are there

range up to 10 mil

Insects dominate in which habitat

terrestrial

crustaceans dominate in which habitat

marine

Arthropods symetry

bilateral

ecdysis

the arthropod sheds its exoskeleton and quickly grows larger before the new exoskeleton hardens

How many classes are in the Arthropod phylum

4

What kind of body cavity

coelomate

description of germ layers

triploblastic

Clade

protostomes, which means it undergoes protostomy during its embryonic development

Circulatory system?

open with well-developed organ systems

reproduction of arthropods

sexual, with separate sexes in almost all. A few are hermaphrodites and some insect and crustacean species are situationally parthenogenetic

example of hermaphroditic arthropods

barnacles

features

exoskeleton, segmented, jointed appendages, ecdysis

What are the subphylums

chelicera, crustacea, Myriapoda, hexapoda,

Subphylum Chelicerata

horseshoe crabs, sea spiders, and arachnids (including scorpions and spiders). They have chelicerae and pedipalps. They consist of predators, parasites, herbivores, scavengers, and detritivores. The aquatic species have gills, and the terrestrial species have book lungs and tracheae

chelicerae

mouthparts of the Chelicerata. Only appendages that appear before the mouth. In most are they are modest pincers used to feed, but in spiders, they are modified for venom injection.

pedipalps

relatively small and are used as sensors, copulatory organs, or for capturing prey.

Subphylum Crustacea

Includes crabs, lobsters, crayfish, shrimp, krill, woodlice, and barnacles. The majority are aquatic and mobile. Some are scavengers, though some are filter feeders, and others are carnivorous. They sexually reproduce with separate genders, and a few species exhibit hermaphroditism

How is the subphylum crustacea distinguish from other arthropods

That have biramous limbs, and larval forms

In which kind of habitat do Arthropods reside?

marine, freshwater, and terrestrial

Subphylum Myriapoda

Previously subphylum Uniramia, includes millipedes and centipedes, they are mandibulate, and are uniramous (single-branched appendages)

Subphylum Hexapod - class insecta

They have 3 body regions and have 3 pairs of legs, which are attached to the thorax. They breathe through the tracheae. They were the first class to master flying

What are the 3 body regions

head, thorax, abdomen

Classes in Subphylum Myriapoda

Chilopoda and Diplopoda

Subphylum Myriapoda - Class Chilopoda

Centipedes, predominantly generalist predators, have a flattened body, are very active, and are mostly nocturnal. They have 1 pair of legs per segment. They reproduce sexually through external fertilization, and some females exhibit parental care.

Subphylum Myriapoda - Class Diplopoda

Millipedes, predominantly herbivores or detritivores, cylindrical body, slow moving, and have 2 legs per segment. They reproduce sexually through external fertilization, and some females exhibit parental care.

Differences between millipedes and centipedes.

Millipedes have 2 pairs of legs per segment, and they are attached to the underside of their body. Centipedes have 1 pair of legs per segment, and they are attached to the sides of their body. Millipedes have no venom, while centipedes have venom. Millipedes are generally adapted for burrowing and are slow-moving, but centipedes are generally adapted for running and move quickly.