Rhinelepini, Armbruster, 2004

Armbruster, Jonathan W., 2004, Phylogenetic relationships of the suckermouth armoured catfishes (Loricariidae) with emphasis on the Hypostominae and the Ancistrinae, Zoological Journal of the Linnean Society 141 (1), pp. 1-80 : 50

LORICARIINAE

Schaefer (1987) suggests that the Loricariinae is the sister to Hypostominae + Ancistrinae (= Hypostominae ; Fig. 2 ), based on the presence of eight or more bifid neural spines and 30 or more preural vertebrae; however, these characteristics appear to be incorrect. In the Loricariinae , there are usually only about five bifid neural spines; Schaefer had probably included the trifid spines (see 127: 1) in his count for the Loricariinae . These trifid spines are a feature unique to the Loricariinae and occur posterior to the dorsal fin. The bifid neural spines are restricted to a region ventral to the dorsal fin. Also, members of the Rhinelepini have less than 30 preural centra. Schaefer also includes two other characters (arrector ventralis of the pectoral girdle passing through a channel, see 163: 0; and presence of the lower lobe of the hypural plate longer than the upper, see 123: 1) as synapomorphies of his Loricariinae + Hypostominae + Ancistrinae ; however, passage of the arrector ventralis through a channel is not found in most hypostomines and a longer lower lobe of the hypural plate is not found in the Loricariinae .

Montoya-Burgos et al. (1998) suggest that the Loricariinae is both closely related to, and derived from within, the Hypostominae , and that Pseudorinelepis is the sister to the Loricariinae . There is no morphological support for Pseudorinelepis as the sister to the Loricariinae ; Montoya-Burgos et al. suggest that there is a phenetic similarity between them, although the taxa share very little other than the loss of the adipose fin in common (a very homoplasious characteristic, CI = 0.09).

In this analysis, the Loricariinae was found to be the sister to the Hypostominae based on the following characteristics: loss of adipose fin (137-1, this is secondarily reversed in most of the Hypostominae ), anterolateral processes of basipterygium slightly angled, do not converge at midline (167: 1), and ventral ridge on basipterygium tall (172: 0). However, as this dataset evolved, the relationships of the Loricariinae were not stable, and these characteristics vary widely among the Hypostominae and Loricariinae ; hence, I have no confidence in the relationship of the Hypostominae to the Loricariinae . None of the characteristics found as synapomorphies are particularly compelling reasons to accept the monophyly of Loricariinae + Hypostominae , the decay index for the node is low (DI = 1), and more research is needed. No attempt was made to ascertain the relationships of the genera of the Loricariinae . For a more complete treatment of the Loricariinae , see Rapp Py-Daniel (1997).

Figures

Figure 2. Phylogeny of the loricariid subfamilies (Schaefer, 1987) and the loricarioid families (de Pinna, 1992).