certainly warrants much additional systematic re- come extinct in the recent decades, and the third
search. One important point, however, is that all species (P. kaufmanni) is threatened (see Birstein
seven of the species surveyed here share twelve os- 1993 and Zholdasova 1997 for review). They were
teological synapomorphies with the tribe Scaphir- endemic to the Amu-Darya and Syr-Darya rivers,
hynchini (Findeis 1997). This conclusion isreflected tributaries of the Aral Sea in Central Asia (Kazakh-
in our classification below. stan, Uzbekistan and Turkmenistan; see Berg
The systematic and conservation status of the 1948a, Tleuov & Sagitov 1973). This region has been
three nominal species of central AsianPseudosca- subjected to extreme environmental degradation,
phirhynchusis unclear. These are the smallest ex- including pesticide pollution and water diversion
tant sturgeons (Figure15).and can be readily distin- projects (Ellis 1990). Sonic classical anatomical de-
guished fromScaphirhynchusby differences in gill scriptions of Pseudoscaphirhynchus were made
raker anatomy and the scalation of the caudal pe- (e.g., Ivanzoff 1887, Sewertzoff 1925), as well as re-
duncle (Findeis 1997). Two of the three species (P. cent embryological studies (Goncharov et al. 1991,
fedtschenkoi andP. hermanni)appear to have be- Schmalhausen 1991), but very few specimens of
Table 7. Preliminary survey of characters
morphic). See Grande & Bemis (1966) for analysis made after this paper was written ( * this character should he scored as a ‘1’).
Char Pol Bir Cho Pei Pal Psep Cro Pol Hus Aci Psu Sea Lep Amifor Figure 17, mostly based on literature (Table 1) (? =unknown, N = inapplicable, P = poly-I. 0 1 11 1111 11 11 00- 01 1 1^11 11 1 111 U0
- 0 1 111111 11 1 1 00
- N 0 11? 111 11 11NN
5. N 0 1 1 ?111 1 111 NN
6. 0 1 1 1 1 1 1 1 1 1 1 0 0
7. 0 1?11111 11 00
8. 00 111 111 11 11 00
9. 0 0 1 1 1 1 1 1 1 1 1 1 0 0 - 0 0 1 1 1 1 1 1 11 11UU
- 0 0 1 1 1 1 1 1 1 1 1 1 1 0
- N 0 1 0 0 0 0 0 00 00 NN
- 0 0 1 0 ?0 0000 0U 00
- 0 0 0 0 1 1 1 1 1 1 1 1 0 0
- 1 0 0 0 1 1 1 1 1 1 1 1 0 0
- 0 0 0 0 1 1 1 1 1 1 1 1 0 0
- 0 0 0 0 1111 1111 00
- 0? 0 0 1111 1111 00
- 0 0 00 1 11 100 00 00
- 0 0 0 0 1 1 1 1 0 0 0 0 0 0
- 0 0 001 11 1 0000 00
- 0 0 001 1 11 0000 00
- 0 0 0 0 1 1 1 1 00 00 00
- 0 0 0 0 1 1 1 1 0 0 0 0 0 0
- 0 0 000 00 011 11 00
- 0 0 000 000 11 11 00
- 0 0 0 0 ?0001111 00
2s. P 0 0 0* 0 0 0 1 1 1 1 P 0 - N 0 0 0? 0 0 0 11 11 NN
30.00 00 0 U00 11 11 00 - 0 0 000 000111 1 00
- 0 0 000 0001 1 11 00
- 0 0 0 0 0 0 U 0 1 1 1 1 0 0
?
???