Crustaceans (part 1)

What are the different Classes of Crustacea

-Branchiopoda
-Cephalocarida
-Remipedia
-Cirripedia
-Copepoda
-Malacostraca

Crustaceans body structure

Eucoelomic
-True coelom
Segmentation
-16 to 20 body segments
Specialised segmentation
-Cephalothorax
Ancestrally biramous appendages

Cephalothorax

Head is fused to the thorax

What makes up crustaceans body wall and what substances reinforces it?

Chitin makes up body wall and calcium carbonate reinforces it

What type of reproduction are crustaceans?

Gonochoristic

What type of larvae crustacea release?

Nauplius

What type of circulatory system crustaceans have?

Open circulatory system (Haemolymph)

What the type of eyes crustaceans have?

Median and Compound

Where is the median eye most predominant in crustaceans?

Larval stages
-Used for orientation

What type of species still contain their median eye in adult stage?

Copepods

Where are compound eyes found in crustaceans?

Either side of head

What ability to compound eyes have?

Some ability to distinguish form and size

In which species compound eyes are colour discriminators?

Stomatopods

What is the process of moulting called?

Ecdysis

In ecdysis of crustaceans what does this process need?

Hormones

What doe hormones of crustaceans do in ecdysis?

Control the resorption of calcium salts and their redeposition in the new outer chitinous skeleton

What factors decreases moulting frequency?

Age and body size

Which organisms in special this factors affect moulting the most?

Malacostracans

What Order is in Branchiopoda?

Cladocera (Water fleas)
-Show cylindrical parthenogenesis
-8 spp

What are the 3 Superorders of Cirripedia?

Acrothoracica
-Burrowers into calcareous material
Rhizocephala
-All parasitic
Thoracica
-Acorn and stalked barnacles

What are the 2 Orders of Thoracica?

Sessilia
-Acorn barnacles
Pedunculata
-Goose barnacles

In Cirripedia are adults hermaphrodites?

Yes
-Do not usually self fertilise

How many naupliar stages are there in Cirripedia?

6

What type of larvae is followed after the 6 naupliar stages of Cirripedia?

Cypris

Example of a parasitic Copepod?

Lepeophtheirus salmonis (sea lice)
-Most damaging parasite to the salmonid farming industry

What is the amount estimated by the paper "The global economic cost of sea lice to the salmonid farming industry" of the total cost lost by sea lice?

305 303 260 euros

Citate ""The global economic cost of sea lice to the salmonid farming industry"

Costello, 2009

What are the three type of appendages found in free-living Copepods? How to distinguish them?

Cephalosome/Prosome
-+5 thoracic segments each with a pair of swimming legs
Urosome
-Abdomen up to 5 segments and no appendages

What does the paper "What makes pelagic copepods so successful?" show?

This paper explores the reasons why Copepods are abundant in our oceans. One of the reasons they used to explain this were their body structure by them containing torpedo-shaped bodiessensory-armed antennules, and specialized muscle motors it allowed

Reasons from the paper "What makes pelagic copepods so successful?" they use?

Body structure
-containing torpedo-shaped bodies sensory-armed antennules, and specialized muscle motors it allows them to escape from predators
Prey detection
-Efficiently detect prey
Mate finding
-Have an efficient mate finding mechanism

Citate "What makes pelagic copepods so successful?"

Kiørboe, 2011

What are the 2 types of planktonic copepods?

Calanoids and Cyclopoids

Key ecological functions of planktonic copepods?

-Key grazers of phytoplankton
-Key food source for juvenile fish

How many developmental stages do calanoid copepods have?

12
-6 nauplius stages (NI-NVI)
-6 copepodite stages (CI-CVI)

What separates each developmental stage of a calanoid copepod?

Moulting

What type of vertical migration do calanoid copepods do?

Ontogenetic Vertical Migration

Ontogenetic Vertical Migration (OVM)

Seasonal movements through the depths of the wate column

Example of OVM

Calanus finmarchicus
-Survives on lipid reserves
-End of winter ascends through water column
-Start of winter descends

What are the 2 main ways of feeding in planktonic copepods?

Ambush feeding and Feeding-current feeding

What type of feeding are all pelagic cyclopoid copepods?

Ambush feeders