MARKINGS OF FISH. 381 



4.— THE MARKINGS OF FISH WITH RELATION 

 TO THEIR ANCESTRAL OR PHYLOGENETIC 

 ORIGIN. 



Bji W. SAVILLE-KENT, F.L.S., F.Z.S., Commissioner of Fisheries, Honortrri/ 

 Member and Past President Royal Society of Queensland. 



The materials which form the suhject of this jjaper having' 

 been primarily derived from investigations conducted in 

 Tasmania, it has occurred to me tliat the outcome thereof 

 might be most appro]iriately communicated to the Hobart 

 meetino- of the Australian Association for the Advancement 

 of Science. 



To the majority of the members present the jDeculiar and 

 highly characteristic markings of all young individuals of the 

 salmon tribe, including notably the Salmon, Salmon Ti'out, 

 and the CommonTrout, will be tolerably familiar and may be 

 easily verified by a visit to the well appointed hatchery 

 established on the River Plenty, within easy access of 

 Hobart. All of the species of fish referred to are remark- 

 able in their early life for the transverse bands, or so-called 

 " par-markings " that are developed in a greater or less 

 number throughout their bodies. As the fish grow older 

 these par-marks gradually disappear and are replaced by the 

 spots or other ornamental markings that characterise the 

 adult fish. So late, however, as the so-called " Smolt " con- 

 dition, representing that stage in the migratory or anadromous 

 Salmonidae, such as the Salmon and Salmon Trout, Sahno 

 snlar and S. trutta, when the body becomes clothed with 

 silvery scales and the fish are ready to start on their journey 

 to the ocean, the removal of the outer silvery coating disj)lays 

 again to sight the original ])ar-markings, which have not 

 actually become obliterated, but simply covered over by later 

 developments. These markings are, in fact, both literally 

 and figuratively more than " skin deep," and are of a far 

 higher physiological significance than the ordinary strijies, 

 spots, and other ornamental markings that blazon what may 

 be termed the overcoat of the fully matured fish. 



Interpreted by the light of the widely recognised laws of 

 physiological evolution, the bars or p;ir-markings shared alike 

 by the young of so many representatives of the same family 

 group signifies that all these now divergent members had a 

 common origin, and that far away back in the prin)eval ages 

 their common ancestor was a permanently striped or par- 

 marked fish. This line of reasoning opens out a wide field 



