ABSTRACT
Contrary to other catfish examined [State 0: e.g. Fig. 3.68], in siluriforms of CS-1 [State 1: e.g. Fig. 3.25], and especially of CS-2 [State 2: e.g. Fig. 3.120], the posterior tip of the bony portion of the autopalatine exhibits a marked lateral incurvation. — CS-0: Posterior portion of autopalatine not laterally curved (all
genera not in other CS) — CS-1: Posterior portion of autopalatine presenting lateral incurvation
( Trichomycterus, Hatcheria, Nematogenys, Callichttiys, Corydoras, Astroblepud
— CS-2: Posterior portion of autopalatine markedly curved laterally (Parakysis, Chaca)
— ?: Since some specimens examined presented a lateral incurvation of the posterior tip of the autopalatine and others not (Akysis)
— Inapplicable: Since in specimens of these genera the portion of the autopalatine situated posterior to the articulatory surface of this bone for the neurocranium is remarkably reduced in size (Loricaria, Hypoptopoma, Lithoxus, Scoloplaid
294. Type of palatine-maxillary system (character inspired from Gosline, 1975). Plesiomorphic situation for Siluroidea seems to be that found in most catfish of this group, in which there is a 'rocking' palatine-maxillary system, that is, one in which the abduction of the maxillary barbel is essentially associated with a mesial displacement of the posterior extremity of the autopalatine (see Diogo et al., 2003a) [State 0: e.g. Fig. 4.21B]. Catfish of CS-1 present a 'sliding' palatine-maxillary system, i.e., a system in which the abduction of the maxillary barbel is essentially associated with posterior displacement of the posterior tip of the autopalatine [State 1: e.g. Fig. 4.22A]. This character is discussed in detail in Chapters 4 and 5. — CS-0: 'Rocking' palatine-maxillary system (all genera not in other
CS) — CS-1: 'Sliding' palatine-maxillary system (Bagrus, Bagrichthys,
H em ibagrus, P im elodus, C alophysus, H ypophthalm us, Pseudoplatystoma, Heptapterus, Goeldiella, Rhamdia)
— ?: Since it was very difficult to appraise this character in the specimens examined (Silurus, Wallago, Rita)
— Inapplicable: Since the palatine-maxillary system of diplomystids differs markedly from that in Siluroidea (see Diogo et al., 2003a) (Diplomystes)
295. Anteriorly directed mesial articulatory surface of autopalatine for neurocranium (character inspired from de Pinna, 1993). Among catfish presenting a mesial articulatory surface of the autopalatine for the neurocranium (see below) the plesiomorphic condition seems to be that in which this articulatory surface is mainly directed posteromesially [State 0: e.g. Fig. 3.33], but in siluriforms of CS-1 this articulatory surface is essentially directed anteromesially [State 1: e.g. Fig. 3.85]. — CS-0: Articulatory surface of autopalatine for neurocranium mainly
directed posteromesially (all genera not in other CS)
— CS-1: Articulatory surface of autopalatine for neurocranium essentially directed anteromesially ( Clarias, U egitglanis, H eterobranchus, H eteropneustes, P lotosus, Paraplotosus, N eosilurus, Cnidoglanis, Chaca)
— Inapplicable: Since these catfish present an articulatory surface of the autopalatine for the neurocranium markedly directed dorsally (see below) (D iplom ystes, N em atogenys, Trichom ycterus, H atcheria, Callichthys, Corydoras, Loricaria, Hypoptopom a, Lithoxus, Scoloplax, Astroblepus)
296. Type of articulation between autopalatine and neurocranium. As noted above, in diplomystid and loricarioid catfish examined the articulatory surface of the autopalatine for the neurocranium is markedly directed dorsally. In primitive cypriniforms and characiforms the articulatory surface of the autopalatine for the neurocranium is situated on the dorsomedial and mesial surface of the autopalatine respectively while such an 'articulation-either direct or indirect via cartilage-is lacking in gymnotoids, even in those forms with a chondroidal autopalatine' (Arratia, 1992: 89). Thus, the comparison with other ostariophysans does not clarify whether the markedly dorsally directed articulatory surface of the autopalatine for the neurocranium represents or not a plesiomorphic situation for the Siluriformes. However, since this is the situation found in diplomystids, the codification of this character is based on the hypothesis that this situation represents the plesiomorphic state [State 0: e.g. Figs. 3.39, 3.67], and hence an essentially mesially directed articulatory surface (see above) represents the derived condition [State 1: e.g. Fig. 3.3], with a detailed discussion of this character given ulteriorly in chapters 4 and 5. — CS-0: Articulatory surface of autopalatine for neurocranium
markedly directed dorsally (D iplom ystes, N em atogenys, Trichom ycterus, Hatcheria, Callichthys, Corydoras, Loricaria, Hypoptopoma, Lithoxus, Scoloplax, Astroblepud)
— CS-1 Articulatory surface of autopalatine for neurocranium essentially directed mesially (all genera not in other CS)
297. Dorsoventral elongation of articulatory surface of autopalatine for neurocranium. Contrary to all other catfish examined [State 0: e.g. Fig. 3.68], in Heteropneustes the articulatory surface of the autopalatine for the neurocranium is remarkably, uniquely elongated dorsoventrally [State 1: e.g. Fig. 3.86]. — CS-0: Articulatory surface of autopalatine for neurocranium not
remarkably elongated dorsoventrally (all genera not in other CS) — CS-1: Articulatory surface of autopalatine for neurocranium
remarkably elongated dorsoventrally (Heteropneustes) 298. Marked incurvation of articulatory surface of autopalatine for neurocranium.
