Gastrosaccus spinifer is found in a wide range of sediment types. In general, the relative occurrence increases in proportion to the median grain size of the sediment up to a maximum relative occurrence of over 60%, which is reached when the median grain size is 450 to 550 μm. Gastrosaccus spinifer does not display an absolute preference for sediments with a specific mud level. However, the species is absent in sediments with a mud content exceeding 70%.
Degraer, S.; Wittoeck, J.; Appeltans, W.; Cooreman, K.; Deprez, T.; Hillewaert, H.; Hostens, K.; Mees, J.; Vanden Berghe, E.; Vincx, M. (2006). The macrobenthos atlas of the Belgian part of the North Sea. Belgian Science Policy. D/2005/1191/3. ISBN 90-810081-6-1. 164 pp. (look up in IMIS)