Neocalanus cristatus (Krøyer, 1848)
One of most biomass dominating copepods of the subarctic Pacific
Size
- Eggs 0.375 mm
- Females 6.2-8.3 mm prosome, 7.7-10.3 mm total length
- Males slightly smaller
Color & Characteristics
- Body nearly transparent, with blotchs of red or orange color on body and usually prominent on both antennae, mouth parts, and parts of the urosome (the tail)
- Prominent low crest on head
- Lipid sac prominent, and up to 50% of body volume
- Urosome (tail) typical length (~ 25% of prosome), with a pair of caudal setae elongated and plumose
- Antennae longer than total length
- Mouth parts and antennae typical of filter feeder
Habitat
- Endemic to sub-arctic Pacific waters, advected seasonally into the arctic and southward into the California Current System
- Most abundant in deeper waters, particularly in offshore or near shelf breaks
- Concentrated in thermocline just below surface mixed layers during growing season, found between 400-1000 m late summer through early winter
Feeding
- Suspension "filter" feeder on phytoplankton and protists
- Large lipids deposits accumulated for summer/fall diapause and to fuel reproduction
- Adults do not feed
- Thought to be one of the sub-arctic's key grazers during spring through early summer in central gyre and nears shelf break
Life cycle
- Females begin spawning at depth shortly after winter soltice using lipid reserves from previous spring, females convert nearly entire body mass into eggs
- Clutch sizes with maximums in excess of 100 eggs and 3-5 clutched produced per female (max total ~500 eggs)
- Nauplii complete development over ~2 months while ascending toward surface, feeding begins at C1
- Rapid growth occurs once the spring bloom begins
- When lipid sac is filled, animal descend to depth as C5, then enter 'diapause' (a form of hibernation)
- after awaking, they molt into adults, mate and spawn over a 1-2 month period
- Generation length and life expectancy, 1 year in the Gulf of Alaska
Page Author: Russ Hopcroft
Created: Jan 14, 2010
