physoclistadj.n.

1872 T. Gill Arrangem. Families Fishes p. xxxvii If a typical physostome fish (e.g., Clupeid) and a specialized physoclyst form (e.g. Perca, Blennius) are contrasted, the differences certainly appear to be considerable.

1887 A. Heilprin Geogr. & Geol. Distribution Animals 303 Both the physoclist and physostome types appear..very nearly simultaneously in the same deposits.

1953 Science 18 Sept. 322/1 The rate of settling observed appears well within the 30% change in pressure to which a physoclist fish, such as perch, can adapt, over a 2–3-hr period.

1887 A. Heilprin Geogr. & Geol. Distribution Animals 303 The severance of the bladder in the physoclists being the result of the disuse of parts.

1893 Proc. Royal Soc. 1892–3 52 147 It is conceivable that a Physoclist, in the course of rapid ascent, might so far depart from its normal plane of equilibrium as to be forcibly carried to the surface of the water, and in that helpless condition fall an easy and conspicuous prey to predaceous Birds or Fishes.

1907 Ann. N.Y. Acad. Sci. 1906–7 17 492 They..tend to connect the physostomes..with the physoclists.

1997 G. S. Helfman et al. Diversity of Fishes v. 63/2 Physoclistous fishes, which include the higher teleosts (Paracanthopterygii and Acanthopterygii), have a closed gas bladder in which the pneumatic duct is sealed off... In physoclists, the gas must be released via the blood.