Marine invert test 4

Cryptobiosis

Ability to shut down everything and reactivate in good conditions

Ecdysis

molting of exoskeleton→ under hormonal control→ have soft shells after molting then they expand and harden up

Terminal molt

final molt→ makes them susceptible to fouling→ being covered by encrusting organisms

Tagmata

Head, thorax, Abdomen

Cephalothorax

head+thorax fused together

Carapace

covering head + thorax

Extensors

extend muscles from inside exoskeleton

Flexors

allow muscles to flex

Chelicere

little mouth parts that look like pinchers

Pedipalps

often modified for Reproduction

Gnathobase

spines projecting off bases of legs

Opisthosoma

has genital operculum followed by several gill opercula→ covers book lungs

Chelifores

look like little claws

Ovigers

used for holding eggs

Mandibles

1st mouth parts

Pereopods

Movement

Pleopods

used for swimming, holding eggs, multiple pairs

Uropods

end pair of legs, enlarged

Telson

extension off of Abdomen, sometimes absent ot modified into other structures with different names

Biramus

endopod, exopod→ may be reduced= uniramus

Subchelate appendage

has a hook

Cheated appendage

has a claw

Nauplius

larval stage→ looks like a football, three distinct appendages on head→ first stage of developement

Class Ostracoda Body Size

0.5-30mm

Class Ostracoda Head

Carapace covers whole body, bivalve, CaCO3 with hinge, set of eyes

Subclass Myodocopa characteristics

Usually antennae notch, Compound+naupliar eye, Heart, Marine

Subclass Podocopa characteristics

Usually no antennae notch, Only naupliar eye, No heart, Freshwater

Class Copepoda Body Size

Few mm in size

Class Copepoda Ecology

Largest component of zooplankton, Main primary consumers in oceanic food webs

Order Calanoida 1st antennae

21-27 segments, half to whole body length

Order Calanoida 2nd antennae

biramus, 10 segments

Order Calanoida Reproduction

Dioecious, 1 egg sac or none, 6 naupliar stages, 5 copepodid stages

Order Cyclopoida 1st antennae

9-23 segments, ¼,- ½ body length

Order Cyclopoida 2nd Antennae

uniramous, 3 segmentts

Order Cyclopoida Reproduction

dioecious, 2 egg sacs, 6 naupliar stages, 5 copepodid stages

Order Harpacticoida 1st antennae

5-14 segments, short, ¼ of body length

Order Harpacticoida Habitat

Benthic

Order Harpacticoida Ecology

meiofauna

Order Siphonostomatoida Head

Mouth cone, maxilla modified into a hook

Order Siphonostomatoida Reproduction

Dioecious, 2 egg sacs, 2 naupliar stages. 1 copepodid, 4 chalimus stages

Class Thecostraca Head

Carapace from mantle tissue, enclosed body. Eyes reduced/absent

Subclass Ascothoracida Head

mouth cone, 1st antennae subchelate (hook-like)

Subclass Ascothoracida Abdomen

4 segments, no appendages

Subclass Ascothoracida Habitat + Digestion

Parasitic in cnidarians or echinoderms

Subclass Cirripedia characteristics

Head: 1st and 2nd Antennae absent; Thorax: appendages as cirri; Abdomen: absent ot reduced; Nauplius with "horns" on front

Infraclass Acrothoracica habitat

bore into limestone (coral, shells,)

Infraclass Thoracica reproduction

monoecious, 4-6 naupliar stages, cyprid stage

Kentrogon

main infection stage

Infraclass Rhizocephala Interna

consists of fungal-like filaments that spread on inside of crab and shrimp

Class Malacostraca thorax

8 segments, female gonopore 6th; Male monitored 8th

Order Leptostraca carapace

bivalve carapace- covers thorax

Order Stomatopoda 2nd maxilliped

enlarged for smashing/speaking prey

Order Stomatopoda reproduction

Antizoea or pseudozoea larvae; Can then turn into Erictus or alima

Order Tanaidacea pereopods

7 pairs pereopods, can be biramous or uniramous, 1st is large and chelate

Order Cumacea pleon

0 pleopods = female; 0-5 pleopods = male

Order Amphipoda body

1-200 mm, compressed side-to-side

Order Amphipoda male gnathopods

greatly enlarged called gnathopods

Order Isopoda body

1-500 mm, compressed top-bottom

Order Mysida oostegites

oval round plates on back end of carapace on females

Order Mysida digestion

omnivores, pereopod "basket" → pereopods come together to form a basket and capture food as they swim through plankton

Order Lophogastrida rostrum

long rostrum present in many (same length as thorax)

Order Lophogastrida uropods

No statocysts on uropods

Order Euphasiacia reproduction

nauplius→ metanauplius→ calyptopus→ furcilia

Order Euphasiacia ecology

upper food web ( one of most important)

Infraclass Acrothoracica males

essentially a sac of gonads

Order Stomatopoda head

eyes- 12 color, 6 uv

Order Mysida uropods

Large uropods with statocysts