Thorson studied planktoniclarvae of marine benthicinvertebrates.[1] He conceived the idea that in the Tropics, benthos tend to produce large numbers of eggs developing into pelagic and widely dispersing larvae, whereas at higher latitudes they tend to produce fewer and larger eggs and offspring.[2][3] This idea was later coined Thorson's rule.[4]
^Thorson, G. (1946). "Reproduction and larval development of Danish marine bottom invertebrates; with special reference to the planktonic larvae in the Sound (Øresund)". Meddelelser Fra Kommissionen for Danmarks Fiskeri- og Havundersøgelser. Serie Plankton. 4 (1): 1–523.
^Thorson, G. (1957). "Bottom communities (sublittoral or shallow shelf)". In Hedgpeth, Joel W.; Ladd, Harry S. (eds.). Treatise on Marine Ecology and Palaeoecology. Memoirs / Geological Society of America. Vol. 67. Baltimore: Waverly Press. pp. 461–534.
^Mileikovsky, S.A. (1971). "Types of larval development in marine bottom invertebrates, their distribution and ecological significance: a reevaluation". Marine Biology. 19 (3): 193–213. doi:10.1007/BF00352809. S2CID84623588.
^"GUNNAR THOROSN in memoriam. 31. Dezember 1906—25. Januar 1971". Internationale Revue der gesamten Hydrobiologie und Hydrographie. 58 (1): 145–146. 1973. doi:10.1002/iroh.19730580110.