| Main Ref. | Sparholt, H., 1990 |
|---|---|
| Remarks | Found on rocky bottoms with sand or mud, or among seaweeds (Ref. 4698). Benthic (Ref. 58426). Feeds on fishes, large crustaceans, occasionally polychaetes, amphipods and benthic invertebrates (Ref. 4698, 12224). Preyed upon by black guillemots. Parasites of the species include 2 protozoans, 2 myxosporidians, 6 trematodes, 1 cestode, 3 nematodes and 4 hirudinoideans (Ref. 5951). |
| Marine - Neritic | Marine - Oceanic | Brackishwater | Freshwater | |
|---|---|---|---|---|
| Marine zones / Brackish and freshwater bodies |
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| Substrate | Soft Bottom Hard Bottom; |
|---|---|
| Substrate Ref. | |
| Special habitats | |
| Special habitats Ref. |
| Ref. | |
|---|---|
| Associations | schooling; shoaling; |
| Associated with | |
| Association remarks | Spawns January-March; catches of males maximal January-February, increased catches of predominantly immature females towards end of spawning period; may be related to different migration patterns in males and females. Possibly after spawning, females migrate to other areas, whereas males stay behind and guard the eggs (Ref. 94977). Larvae display significant active locomotive behaviour immediately after hatching; critical swimming speed increases rapidly with size and age, improving steadily through early larval stages until metamorphosis (onvious transition point linked to settlement, may be attributed to habitat shift associated with settlement and locating a suitable habitat. Unusual swimming behaviour in that individuals did not swim directly into the flow but instead oriented their bodies upward slightly relative to the flow streamlines. This behaviour may be linked to better dispersal by placing individuals in surface waters; important to note that this behaviour was observed in multiple batches of larvae in different years and in different sets of laboratory conditions, suggesting that it is not an artefact (Ref. 94976). Sluggish, often stationary, swims slowly with undulating motion. Except for slight seasonal movement to localities and depths where temperatures are lower, no evidence that they undertake any more extensive seasonal migrations (Ref. 86779). |
| Parasitism |
| Feeding type | mainly animals (troph. 2.8 and up) |
|---|---|
| Feeding type Ref. | Fedorov, V.V., 1986 |
| Feeding habit | hunting macrofauna (predator) |
| Feeding habit Ref. |
| Estimation method | Original sample | Unfished population | Remark | ||
|---|---|---|---|---|---|
| Troph | s.e. | Troph | s.e. | ||
| From diet composition | 3.89 | 3.60 | 0.27 | Troph of adults from 1 study. | |
| From individual food items | 3.76 | 0.79 | Trophic level estimated from a number of food items using a randomized resampling routine. | ||
| Ref. | Bowman, R.E., C.E. Stillwell, W.L. Michaels and M.D. Grosslein, 2000 | ||||