Parasagitta elegans (Verrill, 1873)
The dominant arrow worm of Arctic shelves
Size
- body up to 4.5 cm
Color & Characteristics
- Body firm & translucent, eyes with distinct black spot
- 2 pairs of well separated fins, rounded with complete rays
- Head narow, tail 17-25 % of length
- Each side of head with 9-13 unserrated hooks, 2-10 anterior and 12-25 posterior teeth
- Collarette absent
- Semininal vesicles conical, separated from posterior fins but close to tail fin
- Ovaries thin and short, stretching to back of anterior fins, with large eggs
Habitat
- Arctic and subarctic
- nertic, but not nearshore, epipelagic when in offshore waters
- several subspecies are recognized
Feeding
- An ambush predator, detecting motion with numerous tiny hairs along body
- Pey seized with hooks during a rapid lunge, ratched whole down throat with aid of teeth
- Prey size largely determined by head width
- Diet composed largely of copepods, larvaceans in lower numbers
Life cycle
- Protandrous (releasing sperm first, then producing eggs)
- Fertilized eggs released as stickly masses
- ~1mm at hatching
- generation time unknown, inferred by size-frequency, 1 gerneration per year in Arctic and 2 generations per yea in subarctic
Page Author: Russ Hopcroft
Created: November 15, 2011
