1. ZOO 115 Invertebrate Zoology
Subphylum Crustacea

2. Arthropoda – Subphylum Crustacea
~ 42,000 species
Major trophic link between primary producers (phytoplankton) and higher level consumers
Mostly aquatic
Three part brain
Two pair of antennae
Tactile
Chemosensory
Many legs
Mostly separate sexes
Antennae

3. Subphylum Crustacea
Shrimps and shrimp-like animals

4. Subphylum Crustacea
Lobsters and crawfish

5. Subphylum Crustacea
Crabs

6. Class Branchiopoda Order Anostraca
Can tolerate desiccation and high salinity
15-30 mm in length
Elongate shrimp-like bodies without a carapace
Have stalked compound eyes
Most are suspension feeders
Swim ventral side up
Use their thoracic appendages for capturing food particles
Food is passed to a central groove, encased in mucus and moved forward to mouth.
Gonochoric
Nauplius larvae
Fairy shrimp
Nauplius larvae
Brine Shrimp

7. Class Branchiopoda Order Notostraca
Order Notostraca
Triops (tadpole shrimp)
Tadpole shrimps
None occur in oceans
Feed on organic matter in sediments; some are predators or scavengers
Characteristic broad shield-like carapace and long caudal rami
Triops considered a major pest in rice fields

8. Class Branchiopoda Order Diplostraca
Conchostraca
Clam shrimp
Clam shrimps and cladocerans
Mostly freshwater
Scavengers, predators, detritivores, and suspension feeders
Well developed clam-like carapace
All have a dorsal organ that could function as:
Salt gland
Neck Gland
Adhesion
Swim with their powerful second antenna
Cladocera
Daphnia (water flea)

9. Class Branchiopoda Order Diplostraca
Sexes
Hermaphroditism
Gonochorism
Type of reproduction
Monosexual -Parthenogenesis
Bisexual reproduction - normal sexual reproduction
Eggs
Summer - thin-shelled
Winter - resting
Normal conditions
Females make eggs that hatch without fertilization and become females (2N)
When environmentally stressed
Females produce eggs that hatch into haploid males.
Once the males become mature, the Cladocerans can reproduce sexually.
Parthenogenesis in Cladocera

10. Cladoceran – reproductive strategies
Population all females
Cladocera
Daphnia (water flea)
Stable conditions
Egg
Produces Female identical to adult

11. Cladoceran – reproductive strategies
Population all females
Cladocera
Daphnia (water flea)
Unstable conditions
Swims to new area
Egg
Mates with female
Produces new females but different genetically from adult
Produces Male
Produces Female

12. Subphylum Crustacea Class Malacostraca
Abdomen - 6*
Telson - 1
Head - 5
Thorax - 8*
* Usually
Number of segments
lobster_dorsal_view.jpg
Antenna
Maxilliped
Mandible
Appendages
Head - sensory and feeding
Thoracic - crawling or grasping
Abdominal (unique to this Class and Remipedia) - swimming and copulation
Pleopod
Telson

13. Class Malacostraca Order Stomatopoda
Stalked compound eye
naupliar eye
Mantis shrimps
Specialized predators
No cephalothorax
Head, thorax and abdomen
Two large stalked compound eyes and a third medial naupliar eye

14. Class Malacostraca Order Stomatopoda
Triramous antennae
Specialized prehensile raptorial claws
Has abdominal gills like isopods
Enormous digestive cecum
Very well developed heart and hemal system

15. Class Malacostraca Order Euphausiacea
Krill
All pelagic
Major source of food for whales, squids and fishes
Thoracic gills external to carapace
Feeding basket

16. Class Malacostraca Order Decapoda
Stenopodidea
Cleaner shrimp
Note than third segment is NOT on top of segments 2 and 4
Carid Shrimp
Shrimp-like
IO Caridea (shrimp)
SO Dendrobranciata SF Penaeoidae (prawns)
IO Stenopodidea
Carid Shrimp
Penaeid Shrimp
Palinura – note that the first three periopods are NOT chelate
Thalassinidea – Ghost shrimp
Phyllosoma larve
Lobster-like
IO Astacidea (lobster)
IO Palinura (spiny and slippery lobster)
IO Thalassinidea (ghost shrimp)
Astacidea - First three periopods chelate

17. Crab-like IO Brachyura (True crabs) IO Anomura Brachyura
Brachyura
Crab-like
IO Brachyura (True crabs)
Anomura – note 5th pleopod is greatly reduced and not readily visible
Anomuran Porcelain crab zoea
Note that the fifth pleopod is easily visible
IO Anomura
Anomura – hermit crab

18. Class Malacostraca Order Decapoda
Feeding
6 pair of feeding appendages
1 pr Mandibles
2 pr Maxillae
3 pr Maxillipeds
Most predators and/or scavengers, some suspension feeders, some detritivores, some herbivores, some onmivores

19. Class Malacostraca Order Decapoda
Internal anatomy
Up to 24 pair of gills

20. Class Malacostraca Order Decapoda
Sense organs
Legs
Antennae
1st
Stalked compound eye

21. Class Malacostraca Order Decapoda
Chromatophores
Shrimps especially good at changing color

22. Class Malacostraca Order Decapoda
Reproduction
Most separate sexes (gonochoric)
Sperm transfer – indirect (spermatophores)
Many have copulation
Bachyurans may block fertilization for up to a year following copulation

23. Class Malacostraca Order Decapoda
Lobster
Life cycle
Planktonic larvae of the spiny lobster Phyllosoma larvae

24. Class Malacostraca Order Decapoda
Crab
Life cycle

25. Class Malacostraca Order Mysida
Mysid shrimps
Most 2-30 mm
Gnathophausia - 35 cm
Omnivorous suspension feeders
Well developed carapace and tail fan

26. Class Malacostraca Order Isopoda
Isopods, pill bugs
~10,000 sp
0.5 – 50 cm
Virtually all habitats
Flattened dorso-ventrally
bioephemera.com/wp-content/uploads/2007/09/380353_028542ead3.jpg

27. Class Malacostraca Order Amphipoda
Amphipods
~8000 sp.
1mm-25 cm
In almost every habitat
Flattened laterally
Carapace absent
Gills thoracic
Lives in a Salp
Hyperiidea amphipod
Caprellid amphipod
Gammarid Amphipods