lol Flashcards
What does the term Chaetognatha mean?
Means ‘hairy jaws’
Refers to the structure of their jaws.
What is the typical size range of Chaetognatha?
> 100 mm size
In what type of waters are most Chaetognatha species found?
Marine warm shallow waters
What is the typical behavior of Chaetognatha during the day?
Sink deeper during the day
What role do Chaetognatha play in the planktonic community?
Voracious predators
What is the body form of Chaetognatha?
Small straight bodies, torpedo or dart-like, 1 - 12 cm long
What are the main components of the Chaetognatha body structure?
Head, unsegmented trunk, postanal tail
What covers the body of Chaetognatha?
Thick cuticle
What type of skeleton do Chaetognatha possess?
Hydrostatic skeleton
How do Chaetognatha move?
Highly mobile and nearly transparent, using caudal fins and longitudinal muscles
What do Chaetognatha primarily feed on?
Copepods, fish, and each other
True or False: Chaetognatha have a respiratory or excretory system.
False
What type of reproduction do Chaetognatha exhibit?
Protandrous hermaphrodites
What is the function of the lateral fins in Chaetognatha?
Stabilization and steering
What are the two species of Chaetognatha that have bioluminescent organs?
Caecosagitta macrocephala and Eukrohnia fowleri
How do Chaetognatha detect prey?
Using water vibrations
Fill in the blank: Chaetognatha possess a pair of _______ within the tail.
Testes
What is the lifespan of Chaetognatha?
Variable but short; longest recorded was 15 months in Sagitta
What behavior do planktonic Chaetognatha exhibit to maintain their position in the water?
Hop and sink behavior
How do benthic Chaetognatha typically hunt for prey?
As ambush predators
What percentage of known Chaetognatha species are pelagic?
58%
What do Chaetognatha primarily prey on?
Other planktonic animals, mostly copepods and cladocerans
What neurotoxin do Chaetognatha use to subdue prey?
Tetrodotoxin
What is the main neuromuscular transmitter in Chaetognatha?
Acetylcholine
Fill in the blank: The highest density of Chaetognatha is observed in the _______ zone.
Photic
What is unique about Chaetognatha’s life cycle compared to most marine invertebrates?
Do not undergo metamorphosis nor possess a well-defined larval stage
