Lecture Test 4 Marine Invert- Tardigrada and Arthropoda (part 1)

An organism’s body plan is the following:

• 100 um - 1 mm

• Trunk 

• 4 pairs of legs with hooks, claws or disks

• Thick cuticle molted whole, called exuvium

• Muscle bundles, no longitudinal and circular

What phylum is it?

This body plan describes Phylum Tardigrada

This is an organism’s habitat:

• benthic sand or algae, sometimes barnacle beds

• Interstitial (in between sand grains)

• In freshwater they inhabit moss, saltwater in algae

What phylum is it?

This habitat describes Phylum Tardigrada

Tardigrades have a special thang for sucking cells, what is it called?

• buccal tube with stylets

  • They need this because they aren’t big enough to chew plants so they puncture the cell and suck out the contents

An organism has no circulation, excretion through malphigian glands, and respiration through diffusion. What phylum is it?

It is in phylum Tardigrada

Describe the reproduction and nervous system of phylum Tardigrada

Respiration 

• diffusion (cuticle is thick but not so thick it stops diffusion)

Reproduction

• dioecious 

• Direct development (no larval stage)

• Eggs may be in exuvium (old molted cuticle) 

  • Eggs are giant- 3/4 size of entire body all together

What is the dormancy process for Phylum Tardigrada called?

Cryptobiosis, and they can go dormant for years

What is ecdysis?

- Ecdysis- molting of exoskeleton under hormonal control

- “Hung molts” if they get stuck during molt, they usually die

- Some have a terminal molt and stop growing larger, may get fouled by other organisms

What is they key feature of phylum arthropoda?

Exoskeletons made of chitin (though some arthropods use other materials like calcium for added strength)

True or False: Within arthropods, fewer segments are more ancestral, and more segments are derived.

False, many segments are more ancestral

What are the main body tagmata in arthropoda

1. Head

2. Thorax (head and thorax may fuse to form a cephalothorax)

3. Abdomen

4. Pleon in some groups

Describe the appendages for the arthropod body segments

- Head appendages:

- May or may not have antennae

- Variety of mouth parts for feeding

- Thorax appendages

- Some can be modified for feeding

- Some modified for movement (legs and wings)

- Abdomen appendages

- Most variable, may or may not have appendages

- Appendages usually used for swimming in marine forms

- Some females use for holding eggs

Describe the basic digestive system of phylum arthropoda

- complete (unless parasitic)

- Very specific subdivisions: stomach, intestines, etc

- Large digestive gland in larger specimens

Describe the basic circulatory system of phylum arthropoda

- Open system

- Long tubular heart with Ostia (holes)

- Complex series of arteries to deliver blood

- Sinuses for return of blood

Describe the basic excretion system of phylum arthropoda

Excretion

- excretory organs are glands

- Named for where they exit the body

- Antennae glands (base of antennae)

- Coxal glands (base of legs)

Describe the basic respiration and reproduction system of phylum arthropoda

- small forms = diffusion

- Gills in larger forms

Reproduction

- most dioecious

- Few are monoecious

- There are typically many larval stages (11)

Describe the basic nervous system of phylum arthropoda

• Dorsal brain

• Circum-esophageal connectives that meet on ventral side

• Ventral nerve cord with ganglia in many segments

• Eyes: from blind to simple eye to compound eye

• Sensillae (setae): chemo sensory hairs, tastes things with their feet

• Statocyst, not only for balance but some help with hearing too

An organism has:

• no antennae

• Chelicera: mouth appendage

• Pedipalps (second appendages)

What subphylum is it in?

Subphylum chelicerata

An organism has the following body plan:

- prosoma/cephalothorax

- Covered by carapace

- Chelicera

- Pedipalps: different between males and females: end of pedipalp forms hook in males

- 4 pairs of legs with gnathobase (spines that help chew food outside body)

- Abdomen/opisthosoma

- Genital operculum: where eggs are released

- Gill opercula and book gills (look like pages in book, many leaflets), opercula are thicker and cover book gills

- When very young gill opercula help swimming

- Telson

- Very prominent

- Long spike

- Help them flip over if overturned

- Can help with defense but doesn’t inject anything

What subphylum, class, and order is it?

This is the body plan of the horseshoe crab in Subphylum Chelicerata, Class Merostomata, Order Xiphosura

Describe the habitat, digestion, circulation, excretion, and respiration of an organism in Subphylum Chelicerata, Class Merostomata, and Order Xiphosura

Habitat

- benthic

- Shallow water

- Sand

Digestion

- food groove is external

- Crop and gizzard after mouth area

- Omnivores

Circulation

- arthropod plan, blood with henocyanin (blue blood when oxygenated)

Excretion

- 4 pairs coxal gland

Respiration

- book gills

An organism has the following reproduction:

• dioecious

• Males are smaller with hooked pedipalps

• Mass spawning

• Females nest on beaches at high tide line

• Male and females meet in shallow water, male hitches a ride to sand, put eggs in sand

• Trilobite larva

What subphylum, class, and order is it?

This is the reproduction of the horseshoe crab in Subphylum Chelicerata, Class Merostomata, Order Xiphosura

An organism has the following traits:

Body plan:

- thorax

- 4 pairs biamorous thoracopods

- Abdomen: unsegmented, no appendages

- Parasites usually modified

Habitat and digestion

- ectoparasite on fish

Reproduction

- dioecious

- Metanauplis

Ecology

- fish issues including aquaculture facilities, not as dense in ocean

What phylum, subphylum, and class is it in?

Phylum Arthropoda, Subphylum Crustacea, Class Branchiura

An organism has the following body plan:

- 0.5-30mm

- Carapace is bivalve with CaCO3, hinge and adductor muscles

- Eyes variable

- 2nd antennae enlarged

- 2nd maxillae present

- Thorax: 1-3 pairs biramous thoracopods

- Abdomen: greatly reduced, no appendages

What phylum, subphylum, and class is it in?

Phylum Arthropoda, Subphylum Crustacea, Class Ostracoda

Describe the habitat, feeding, reproduction, and ecology of an organism in class ostracoda

Habitat

- planktonic and benthic, benthic larger than plankton usually

Feeding

- all types

Reproduction

- direct development through instars (basically smaller version of adult, no metamorphosis)

- Bred within carapace, leave mom when juveniles

- Bioluminescence (Bon Air bioluminescence)

- Used during mating and as defense

- “Sea fireflies”

Ecology

- minor part of food web

- Long fossil record

An organism has the following features:

• antennae notch in carapace, front end

• Compound and naupliar eye

• Heart

• Mostly marine 

Is it an ostracod in subclass myodcopa or subclass podocopa?

It’s in subclass mycopoda

An organism has the following features:

- no antennae notch

- No compound eye- naupliar eye

- No heart

- Mostly freshwater, some marine

Is it an ostracod in subclass myodcopa or subclass podocopa?

It’s in subclass podocopa.

Describe the body plan of class copeopoda

• free living and parasitic

• Largest component of zooplankton in freshwater and saltwater

• Main base of primary consumers in ocean food web

Body plan 

• few mm

• Parasites generally larger than free living forms 

• Head:

  • No carapace 

  • Large first antennae 

  • Small second antennae

  • Naupliar eye (named from naupliar stage and doesn’t develop further than that)

• Thorax:

  • 1st and maybe 2nd, fused with head

  • With appendages

• Abdomen

  • No appendages

  • Caudal rami at end 

An organism has the following body plan:

• first antennae has 21-27 segments (as long or longer than body)

• Second antennae biramous, 10 segments

• Thorax:

  • 1st fused to head

  • 1 pair maxillipeds

  • 5 pairs biramous perepods

  • Very efficient swimmers

What Phylum, Subphylum, Class, and Order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Copeopoda, and Order Calanoida

What is the habitat, digestion, reproduction, and ecology of the calanoid copeopods?

Habitat

- planktonic

Digestion

- omnivores

- Cyclical feeding in some situations, food is still alive when excreted in some situations because they eat so much in high density

Reproduction

- dioecious

- 1 egg sac or more

- 6 naupliar larval stages

- 5 copeopodid larval stages

- With each molt, they add something to body until adulthood

Ecology

- very important group, 1 of two dominant copeopod groups

An organism has the following body plan:

• first antennae 9-23 segments, 1/3-1/2 body length

• Second antennae uniramous 3 segments

• Naupliar eye

• Thorax:

  • 1st and 2nd fused to head

  • 1 pair maxillipeds

  • 5 pairs biramous preopods

What Phylum, Subphylum, Class, and Order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Copeopoda, and Order Cyclopodia

What is the habitat, digestion, reproduction, and ecology of the cyclopodia copeopods?

Habitat

• planktonic

Digestion 

• omnivores 

• Slightly smaller than calanoids

Reproduction

• dioecious

• 2 egg sacs

• 6 naupliar stages

• 5 copeopod larval stages 

Ecology

• 1 of 2 dominant planktonic groups of copepods

An organism has the following body plan:

• First antennae 5-14 segments, usually 1/4 body length

• Second antennae biramous 2-8 segments

• Naupliar eye

• Thorax 

  • 1st and 2nd fused to head

  • 1 pair maxillipeds

  • 5 pairs biramous preopods

  • Narrow body

What Phylum, Subphylum, Class, and Order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Copeopoda, and Order Harpacticoida

What is the habitat, digestion, reproduction, and ecology of the Harpacticoida copeopods?

Habitat

• benthic, sand and mud especially

Digestion

• omnivore, deposit feed 

Reproduction

• dioecious

• Single egg sac

• 6 naupliar larval stages

• 5 copeopodid larval stages

Ecology

• important part of benthic meiofauna 

The following organism is described:

Body plan

• head

  • Mouth cone

  • Maxillae form some kind of hook

• Thorax and abdomen

  • Highly variable based on species

Habitat and digestion

• adults parasitic on fish and inverts

Reproduction

• dioecious

• 2 egg sacs

• 2 naupliar larval stages

• 1 copeopod larval stage

• 4 chalimus larval stages

• Eventually latches on and becomes adult parasite

Ecology

• fish issues

What Phylum, Subphylum, Class, and Order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Copeopoda, and Order Siphonostomatoida

An organism has the following body plan:

• carapace from mantle tissue that encloses body

• Nauplius larval stages

• Cryprid larval stage

What phylum, subphylum, and class is it?

Phylum Arthropoda , Subphylum Crustacea, Class Thecostraca

An organism has the following body plan:

• few mm

• Mouth cone- diagnostic modification

• 1st antennae subchelate- diagnostic

• 2nd antennae absent

• No eyes

• Bivalve carapace not calcified

• Thorax:

  • 6 segments

  • 3-6 pairs thoracopods

• Abdomen:

  • 4 segments

  • No appendages

What phylum, subphylum, class, and subclass is it?

Phylum Arthropoda, Subphylum Crustacea, Class Thecostraca, Subclass Ascothoracida

What is the habitat, digestion, reproduction, and ecology of a crustacean in subclass Ascothoracida (Class Thecostraca)

• Habitat

  • Adult parasitic in cnidarians and echinoderms (hence head modification)

• Digestion

  • Parasitic

• Reproduction

  • Dioecious

  • 4-6 naupliar larval stages

  • Cyprid stage (some hatch as cyprid)

• Ecology

  • Minor parasite

Describe sublass cirripedia in class thecostraca.

• usually with thoracopods as long biramous cirri

• Abdomen reduced to absent

• Nauplius larva with “horns” on front edge 

What is the habitat, digestion, reproduction, and ecology of Infraclass Acrothoracica (subclass cirripedia)

• Habitat

  • Females bore into limestone structures forming pits in coral, shells, tests

  • For this IC, females dissolve oval shell, for boring sponge it’s a round hole

• Digestion

  • Filter feed (female)

  • Non feeding (Male)

• Reproduction

  • Dioecious

  • 4-6 naupliar larval stages

  • Cyprid stage

• Ecology

  • Very minor part of food web

A cirriped has the following body plan:

• few mm - few cm

• Head

  • 1st and 2nd antennae absent

  • Vestigial naupliar eye

  • Carapace made from multiple calcified plates 

• Thorax

  • 6 pairs long cirri

  • 6 segments

• Abdomen

  • Reduced to absent

Is it in infraclass thoracia or infraclass rhizocephala?

It’s in infraclass thoracia

What is the habitat, digestion, reproduction, and ecology of Infraclass thoracica (subclass cirripedia)

Habitat

• attached to structure (almost anything in water)

Digestion

• filter particulate with cirri 

Reproduction

• Monoecious

• 4-6 naupliar stages

• Cyprid stage

Ecology

• major component of rocky shores

• Barnacle zone

• Zoobios on whales, turtles, and other crustaceans

• Harvested for food, not in US but in Spain 

A cirriped has the following body plan:

Body plan

• few mm to few cm

• Everything is absent, highly modified parasite

• Typical Cirripedia nauplius larva

• Female: interna (filaments inside body of host) and externa (egg sac outside body of host)

• Dwarf males: short lived only for reproduction with external 

Is it in infraclass thoracia or infraclass rhizocephala?

It is in infraclass rhizocephala.

What is the habitat, digestion, reproduction, and ecology of Infraclass Rhizocephala (subclass cirripedia)

Habitat

• females parasitic in other crustaceans

Digestion

• female parasitic filaments (interna)

Reproduction

• dioecious

• 0-6 naupliar stages 

• Cyprid stage

• Kentrogon stage in many- final infective stage 

Ecology

• causes major changes in infected crustaceans ie molting, growth, reproduction

An organism has the following body plan and reproduction:

• 8 segments on thorax (may be chelate, subchelate, or simple)

  • Female gonopore 6th segment

  • Male gonopore 8th segment

• Pleon: 

  • Usually 6 segments

  • Preopods number variable across orders and sexes

  • Most pleopods biramous, some may be uniramous

• Uropods usually present, variable in size and shape across orders

• Telson:

• Usually present 

• Reproduction

  • dioecious in most

  • Many different larval stages- diagnostic for group

What phylum, subphylum, and class is it in?

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca

An organism has the following body plan:

- 1-40 mm

- Larger spp are usually deep water or Antarctic

- Head:

• Eyes

• Bivalve compressed carapace covers thorax

• Hinged rostrum

• Adductor muscle

- Thorax:

• No distinction between mexillipeds and pereopods

• 8 pairs biramous, foliaceous thoracopods

- Pleon:

• 7 segments (only group of Malacostraca with 7 segments on Pleon)

• 6 pairs pleopods

- Very end has 3 names: uropods, telson, and caudaul rami

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Leptostraca

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Leptostraca.

What is its habitat, digestion, reproduction, and ecology?

Habitat

• benthic 

Digestion

• particulate 

Reproduction 

• hatch as manca/small juvenile 

• Planktonic advanced stage because female broods larva, manca is essentially one molt before adult

Ecology

• minor part of benthic food web 

An organism has the following body plan:

• 5-55 cm

• Head:

  • Very well developed eyes, 12 color and 6 UV receptors

  • Eyes operate separately giving near 360 degree vision, can point both eyes forward for binocular vision

• Carapace extending over first 4 thorax segments, short compared to rest of body

• Thorax:

  • 5 pairs of subchelate specialized maxillipeds, distinctly modified for feeding

  • 2nd pair of maxillipeds enlarged to spear or smash prey, “raptoral claw (spelling?)”

  • 3 pairs biramous pereopods, used for walking

• Pleon:

  • 5 sets of pleopods with gills

• Uropods large

• GILLS AROUND PLEOPODS, instead of further up, unique

• Telson:

  • Very broad

  • Diagnostic for lower levels

What phylum, subphylum, class, and order is it in?

This is the body plan for the mantis shrimp, Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca Order Stomatopoda

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca Order Stomatopoda.

What is its habitat, digestion, reproduction, and ecology?

Habitat

• benthic, construct burrow

• shrimp in reefs scrape out a crevice

Digestion

• carnivore 

• Spearers feed on fish, smashers feed on other inverts

Reproduction

• hatch as antizoea larva OR pseudozoea larva 

• Develop into erichthus larva or alima larva

Ecology

• predators in shallow water

Other 

• aquarium trade, especially peacock mantis shrimp 

• Harvested for food

An organism has the following body plan:

• 5-20 mm 

• Head:

  • Reduced eyes 

  • Carapace extending over first 2 thorax segments, very short

• Thorax

  • 1 pair maxillipeds

  • 7 sets of pereopods, bi or uniramous

  • First pereopod set enlarged and chelate 

• Pleon:

  • Relatively compact

  • 0-5 pairs Pleopods

  • Uropods slender

• Telson often fused with last abdominal segment 

What phylum, subphylum, class, and order is it in?

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Tanaidacea

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Tanaidacea.

What is its habitat, digestion, reproduction, and ecology?

Habitat

• benthic

• Many in sand

• Some build small tubes of glued sand grains

Digestion

• deposit

Reproduction

• Hatch as manca larva 

Ecology

• minor part of food web

An organism has the following body plan:

• “walnut with tail” 

• 1-4 mm

• Head

  • Reduced eyes

  • Carapace covers first three thoracic segments

  • Carapace area enlarged compared to rest of body

  • Different ornamentation on carapace diagnostic for lower levels

• Thorax

  • 3 pairs maxillipeds

  • 5 pairs pereopods, bi or uniramous 

• Pleon

  • Females: 0 Pleopods

  • Males: 0-5 Pleopods

• Uropods slender

• Telson is long but shorter than uropods

What phylum, subphylum, class, and order is it in?

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Cumacea

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Cumacea

What is its habitat, digestion, reproduction, and ecology?

Habitat

• benthic in sand

Digestion

• deposit feeders in sand

Reproduction

• hatch as manca larva 

Ecology

• minor part of food web

• Cretaceous fossils

An organism has the following body plan:

- 1-200 mm, compressed side to side

- Head:

• Varying size of eyes

• No carapace

- Thorax

• 1 pair maxillipeds

• 7 pairs uniramous pereopods

• Pereopods 1 and 2 often subchelate and enlarged in males- referred to as gnathopods in males

- Pleon

• 5 sets Pleopods (reduced in some spp)

- Uropods slender

- Telson

What Phylum, subphylum, class, and order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Amphipoda

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Amphipoda.

What habitat, digestion, reproduction, and ecology do they have?

Habitat

- benthic

- Skeleton shrimp hang onto things

- Some planktonic (few mm), very good vision

- Some terrestrial, some freshwater

Digestion

- all feeding types

Reproduction

- Hatch as small juveniles, no larval stage

- VERY unusual to come out as juveniles and not manca larva or less developed

Ecology

- part of benthic, planktonic, and shoreline food webs

An organism has the following body plan:

- 1-500 mm, compressed ventral to dorsal

- Large eyes

- No carapace

- Thorax:

• 1 pair maxillipeds

• 6-7 pairs uniramous pereopods

• Pereopods: 1-3 are subchelate

- Pleon

• Pleopods variable in size, used for respiration

- Uropods may be reduced

- Telson usually fused to last abdominal segment

What Phylum, subphylum, class, and order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Isopoda

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Isopoda

What habitat, digestion, reproduction, and ecology do they have?

Habitat

• benthic 

• Some parasitic on fish 

• Some terrestrial, some freshwater

• Benthic deep sea giant

Digestion

• all feeding types

Reproduction

• hatch as manca larva 

Ecology

• benthic food webs Subphylum Crustacea

• Minor issue as parasite

An organism has the following body plan:

• Tend toward larger end of spectrum

• Head

  • Eyes

  • Carapace covers thorax but only fused to first 3 segments

  • Medium to long rostrum 

• Thorax

  • 1 pair maxillipeds

  • 7 pairs biramous pereopods

  • Gills present 

• Thorax

  • Females have 7 oostegites, marsupium holds eggs

• Pleon

  • 5 pairs Pleopods

• Uropods without statocysts

• Telson

What Phylum, subphylum, class, and order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Lophogastrida

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Lophogastrida.

What habitat, digestion, reproduction, and ecology does it have?

Habitat

• planktonic deeper water

• Red shrimp zone

Digestion

• carnivore

• Pereopod basket

Reproduction

• leave pouch/marsupium as small juveniles

Ecology

• minor part of deep water food web

An organism has the following body plan:

• 4-150 mm

• Head

  • Good eyes

  • Carapace covers entire thorax length, but only 1/2 to 3/4 of the way down the sides 

• Thorax

  • 7-8 pairs long biramous thoracopods with exposed gills

• Pleon

  • 5 pairs Pleopods

• Uropods and telson present

What Phylum, subphylum, class, and order is it?

Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Euphausiacea

An organism is in Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Euphausiacea

What habitat, digestion, reproduction, and ecology does it have?

Habitat

• planktonic in massive swarms 

• Larger shrimp may be nekton because they swim up and down, but not against strong current

• Across very big depth zone

Digestion

• omnivores

• Thoracopod basket

• Very feathery net like legs, Antarctic ones scrape ice for food

Reproduction

• nauplius larva

• Metanauplius larva

• Calyptopis larva

• Furcilia larva 

• Lots of larva stages!

• Last two are unique to krill

Ecology

• huge part of middle food web: fish, seals, whales, sharks, birds

An organism has the following body plan:

• body

  • Few mm

  • Big difference between M and F

    • Male- sac of gonads with short antennae, short lived, morphology based of F

    • Female- no first or second antennae, usually no eyes, carapace not calcified

  • Thorax

    • 6 segments

    • 0-1 pair maxillipeds

    • 3-6 pairs cirri

  • Abdomen reduced to absent

What phylum, subphylum, class, subclass, and infraclass is this?

This body plan is Phylum Arthropoda, Subphylum Crustacea, Class Thecostraca, Subclass Cirripedia, Infraclass Acrothoracica