Sexually ripe specimens have been observed in April and May. Most probably the larvae have a planktonic development. E. longissima lives in burrows. When conditions become unfavourable it will rapidly and repeatedly move and set up a new tube at other locations. E. longissima is mainly a non-selective deposit feeder, feeding on algae and dead animals. The species itself is eaten by flatfish (Hartmann-Schröder, 1971; Wolff, 1973; Fauchald & Jumars, 1979).

Baie de la Seine, Belgian Exclusive Economic Zone, European waters (ERMS scope), Golfe Normanno-Breton, Greek Exclusive Economic Zone, Irish Exclusive economic Zone, Plymouth, Portuguese Exclusive Economic Zone, Roscoff, Spanish Exclusive Economic Zone, United Kingdom Exclusive Economic Zone, Wimereux

N. longissima occurs from the subtidal zone of the Wadden Sea and the Delta area down to a depth of 50 m in the Oyster Ground, where it is quite abundant. In the offshore part of the Southern Bight N. longissima is almost absent.

With only eight observations and a maximum density of 16 ind./m2 Eunereis longissima was a rare phenomenon in the entire near-coastal zone in the 1976-1986 period. In the 1994-2001 period the number of observations increased and densities up to 100 ind./m2 were noted. The species still mainly occurred near the coast, but clearly avoided the eastern coastal zone.

A species with a long, rather flattened body of up to 150 mm in length, with over 200 segments. The head is conical, truncate, with two frontal antennae, two biarticulate palps and four relatively small eyes. The first segments bears four pairs of cirri. Like all nereids, the species has an eversible proboscis and two terminal jaws. The small number of teeth on the proboscis are characteristic for this species. The body segments are rather uniform, with prominent, powerful parapodia bearing distinct lamellae. lt is blue-grey, reddish or pinkish in colour (Hartmann-Schröder, 1971; Hayward & Ryland, 1990).

The bristle worm Eunereis longissima can reach a length of up to 50 cm, although only smaller specimens with a maximum length of 20cm have been found on the Belgian part of the North Sea. The striking head structures with tentacles, palps, antennae and four eyes are characteristic. Living specimens have a red to iridescent dark brown colour.

Eunereis longissima is typically found in sediments with a median grain size of 100 to 250 µm. The species has a broad mud content tolerance but tends to prefer (relative occurrence: > 50%) sediments with a mud content of 10-20%.

Its density distribution suggests a preference for substrates with an admixture of mud.

Depth range based on 863 specimens in 1 taxon.
Water temperature and chemistry ranges based on 278 samples.

Environmental ranges
  Depth range (m): -0.4 - 1351
  Temperature range (°C): -0.961 - 13.512
  Nitrate (umol/L): 0.459 - 15.301
  Salinity (PPS): 18.622 - 38.505
  Oxygen (ml/l): 5.301 - 6.915
  Phosphate (umol/l): 0.237 - 1.178
  Silicate (umol/l): 2.052 - 28.168

Graphical representation

Depth range (m): -0.4 - 1351

Temperature range (°C): -0.961 - 13.512

Nitrate (umol/L): 0.459 - 15.301

Salinity (PPS): 18.622 - 38.505

Oxygen (ml/l): 5.301 - 6.915

Phosphate (umol/l): 0.237 - 1.178

Silicate (umol/l): 2.052 - 28.168
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1