crenobionta, Gasterosteus aculeatus forma Băcescu [M. C.] & Mayer [R.] 1956:24, Figs. 2b, 3c, e, 4b, d [Buletinul Institutului de Cercetari Piscicole. v. 15 (no. 2); ref. 21859] Lake Techirghiol, Romania. Syntypes: MGAB 49912a-b (2). Type catalog: Mihai-Bardan 1984:460 [ref. 21542] with a holotype. Apparently acceptable as a forma = subspecies before 1961 (see Art. 45.6.4 of the Code). •Synonym of Gasterosteus aculeatus Linnaeus 1758 -- (Paepke in Bănărescu & Paepke 2002:209 [ref. 25856]). •Valid as Gasterosteus crenobiontus Băcescu & Mayer 1956 but extinct -- (Kottelat 1997:165 [ref. 22952], Kottelat & Freyhof 2007:493 [ref. 29996]). Current status: Valid as Gasterosteus crenobiontus Băcescu & Mayer 1956. Gasterosteidae. Distribution: Freshwater springs, Lake Techirghiol, Romania [extinct]. Habitat: freshwater.