Cruciglanis , a new genus of Pseudopimelodid catfish ( Ostariophysi : Siluriformes ) with description of a new species from the Colombian Pacific coast

Cruciglanis pacifici, gen. et sp. nov., is described from the Dagua and Anchicaya Rivers on the Pacific slope of Colombia. The new genus is differentiated from the other genera in the family by the presence of an ossified crucifix-shaped second basibranchial; ectopterygoid bone shaped as an inverted comma, with its distal end narrow and directed medially towards the mesopterygoid; anterior fontanel elongated, reaching a transverse line at sensory canal opening of the sphenotic bone; caudal fin emarginated with rounded edges and ventral lobe more developed than the dorsal lobe; caudal fin with a dark spot from its base and fused with the peduncular spot, covering the anterior three quarters of its length, distal rim totally hyaline. Coloration of the species is described in vivo, and the shared diagnostic characters with the other genera within the Pseudopimelodidae are discussed. The phylogenetic position of the new genus is proposed and new insights in the family interrelationships are presented.


Introduction
The Neotropical catfish family Pseudopimelodidae (sensu Shibatta, 2003a: 401) is found from the Atrato River in Colombia to Argentina in the Río de la Plata.The wide distribution and the scarcity of specimens in collections in part due to the size of some species have contributed to a delayed phylogenetic study of this family.In the first revision of the group three genera were proposed as valid: Pseudopimelodus, Microglanis y Lophiosilurus (Mees, 1974).Later, the genera Cephalosilurus, Zungaro and probably Zungaropsis were included (Lundberg et al., 1991: 204).Shibatta (1998: 87) carried out a phylogenetic analysis of the Pseudopimelodidae family based on 55 morphologic characters, considering the genus Pseudopimelodus as polyphyletic and a basal group in his analysis.This supports the Lundberg et al. (1991) hypothesis where this genus (called Zungaro by the authors) is presented as closely related to the other Pseudopimelodidae (Shibatta, 2003b: fig. 13.4).Additionally, Batrochoglanis was added as valid genus and Zungaro and Zungaropsis are invalidated because they share synapomorphies proposed for the Pimelodidae (de Pinna, 1998;Shibatta, 2003b: 394).Currently, Zungaropsis is considered as a genus inquirendum of the Pimelodidae (Lundberg & Littmann, 2003: 443) thus confirming the incipient knowledge about this family.Lundberg et al. (1991: 204) proposed the following synapomorphies for the Pseudopimelodidae: (1) Lateral ethmoid projecting beyond the condyle of the palatine, with the tipshaped wing of membranous bone lost.This structure is projected beyond the condilo of the palatine (Lundberg et al., 1991: 194, figs. 2c-d) ; (2) Very short metapterygoid, dorsally curved towards the inner part and generally supported by a crest or rim (Lundberg et al., 1991: 200, fig. 9c); (3) Endopterygoid (=mesopterygoid in Shibatta, 1998) and ectopterygoid wide, with a distinct shape (where in the former, the antero-lateral process has a sharp tip and the latter has a comma shape) and being loosely linked between the neurocranium from the proximity of the orbitsphenoid suture and the lateral ethmoid to the autopalatine (Lundberg et al., 1991: 194, fig. 2c-d); (4) Third to the seventh (last) proximal radials of the dorsal fin wide with adjacent rays in close contact for all their length (large pseudopimelodines, see Lundberg et al., 1991: 196, fig. 5d), and a bit separated in Microglanis; (5) Absence of hypohyal dorsal bones.Diogo et al. (2004: 273) confirmed the synapomorphies supporting the monophyly of the group.Additionally, they proposed two new potentially diagnostic characters for Pseudopimelodidae, based on a phylogenetic analysis that included 440 characters and 87 terminal taxa representing all existing catfish families: (1) mesethmoid markedly bifurcated and (2) spoon-like autopalatine with a roundish, dorso-ventrally expanded posterior tip.
Batrochoglanis transmontanus (Regan 1913) has been the only representative of the family described or mentioned in the Pacific basin of Colombia.The present work makes a diagnosis of Cruciglanis, collected in the Dagua and Anchicayá River basins, as a new genus grouped in the family Pseudopimelodidae, according to the synapomorphies suggested by Lundberg et al. (1991), and confirmed by Shibatta (1998Shibatta ( , 2003a, b), b).

Material and Methods
Morphometric data are straight line distances, between defined landmark points based on the methodology proposed by Bookstein et al. (1985).The measurements are adapted from Littmann et al. (2000).The following measurements were taken using a dissecting microscope and a digital caliper with a precision of 0.05 mm: head length, measured from the tip of the snout to posterodorsal angle of the opercle; snout length, from the tip of the snout to the anterior rim of the eye orbit; interorbital length measured between the inner rims of the eyes; mouth width, measured from one commissure to the other; barbel distance using the center of the barbel's base as the landmark point.Predorsal, prepectoral and preventral distances were taken from the tip of the snout to the base (origin) of the first ray or bony element in the corresponding fin; the cleithral width was taken between the insertion of the pectoral spines.The distances between fins were taken from the landmark points using the term "origin" as the first ray or bony element and insertion as the most distal point of the last ray.The center of the hypural was defined as the medial point in vertical direction from the end of the hypural complex.The depth of the caudal peduncle is the minimum height in vertical direction at the end of the adipose fin.
The external anatomic descriptions and comparisons are based on alcohol preserved museum specimens.Osteological descriptions and comparisons were done using dried skeletons (dpo) prepared with the help of Dermestids colonies.Cleared and counter-stained (c&s) specimens with alizarin and alcian blue, were prepared using the modifided technique proposed by Dingerkus & Uhler (1977), Estrada (1977) and Taylor & Van Dyke (1985).The number of gill rakers, vertebrae, fin rays, branchiostegal rays and ribs were obtained using only cleared and stained specimens.The vertebral counts included the five vertebrae of the Weberian complex.The bone complex of the caudal fin is counted as a single vertebra.

Cruciglanis, new genus
Type species: Cruciglanis pacifici, new species.Etimology.Genus Cruciglanis, from the Latin crucis, cross; and glanis, meaning catfish, in allusion to the crucifix shape of the second basibranchial in the branchial arch.Gender: Masculine.

Cruciglanis pacifici, new species
Fig. 1 Holotype Diagnosis.As for the genus.
Description.Morphometric characters of holotype and nine paratypes given in Table 1, meristic characters given in Table 2. Body cylindric, relatively elongated, 26.2-28.8% of SL; head moderately depressed, bones covered by skin; supraoccipital process wider at base than posteriorly with bifurcated tip contacting supraneural, blunt tipped and convexly sided (Fig. 4a); fontanels not visible through skin, anterior fontanel elongated reaching transverse line through opening of infraorbital sensory channel in sphenotics (Fig. 4a); posterior fontanel small and oval-shaped, located in center of supraoccipital.Eye small, covered by skin, in latero-dorsal position; anterior nostril tubular and separated from lip rim; posterior nostril closer to eye than to anterior nostril (Fig. 1); mouth wide (56.3-64.6% of HL), upper jaw projecting slightly beyond lower; upper and lower lip subdivided in two fleshy rims parallel to snout margin.Teeth small, villiform; premaxilae laterally projected backwards (Fig. 3a), dentary symphysis straight.Maxillary barbel inserted on upper lip anterior to anterior nostril, reaching base of pectoral spine.External mental barbel inserted at same level of gular fossa apex reaching branchial opening ventrally.Internal mental barbel inserted anterior to gular fossa apex, reaching symphysis of branchiostegal membrane; branchiostegal membrane free from isthmus; gular fossa V-shaped, with sharply pointed but inconspicuous apex (Fig. 1).Anterior mesial margin of mesethmoid anterior to premaxillary posterior mesial margin (Fig. 3a); vomer present, T-shaped and contacting parasphenoid and mesethmoid but not lateral ethmoid, without interdigitating joints with mesethmoid and parasphenoid (Fig. 3a).Autopalatine posteriorly expanded dorso-ventrally; metapterygoid with antero-lateral upper projection more developed than lower; levator crest palatine arch moderately developed.Dorsal-fin origin on first third of body, posterior edge convex; dorsal spine strongly ossified, shorter than following branched ray, posterior edge of dorsal spine with two distal serrae.Pectoral-fin spine serrated, covered by skin, anterior margin with 11-15 serrae of similar size and posterior  margin with 8-11 serrae larger than on anterior side, increasing progressively in size and curvature from base distally; posterior edge of pectoral fin convex; mesocoracoid arch elongated, stick-shaped in 90º angle; posterior cleithral process thin, sharp and long, longer than half of adducted pectoral spine; axillary pore absent.Pelvic fin rounded inserted behind end of dorsal-fin base.Anal fin with rounded posterior edge and inserted below 15 th or 16 th vertebra.Caudal fin emarginated, with rounded lobes and inferior lobe slightly more developed and longer than dorsal (Fig. 5a).Adipose fin 12.3-14.2% of SL, originating at level of anal-fin origin, posteriorly rounded and free from caudal peduncle (Fig. 1).
Color in life.Dorsal region of head, lateral surface of body, and adipose fin brown, ventral region cream (beige) with some brown spots.Four dark brown vertical marks on sides, first on occipital region; second completely crossing base of dorsal fin, joining first just behind posterior cleithral process and reaching anterior portion of belly; third mark crosses through base of adipose fin and extends onto middle anal-fin rays, third mark also joining dorsal portion of second mark by two bands that flank back of body between dorsal and adipose fins, forming clear oval-shaped spot that extends dorsally from insertion of dorsal fin to origin of adipose fin (Fig. 6); fourth mark covers first three fourths of caudal fin; posterior quarter of caudal fin hyaline (Figs.5-6).Pectoral, dorsal, anal, and adipose fins dark, except for completely hyaline or semitransparent posterior rims (variable clear area on adipose); pelvic fins generally clear except at their base where some dark pigmentation occurs.Pattern above shows very little variation among specimens observed (Fig. 6).
Color in alcohol.Body coloration pattern conserved in alcohol, but some general changes occur in color tones.Dorsal region of head and dorso-lateral area of body with dark grayish brown tone, body lateral surface turns gray-purple, and cream (beige) color intensified on ventral region of body and head.Brown spots present in life turn maroon, and semitransparent areas observed in vivo turn white (Fig. 1).
Etymology.The specific name, pacifici, is treated as a noun in apposition, in allusion to the endemic distribution of this species in the coastal rivers draining the western slope of the Cordillera Occidental of Colombia.Distribution.San Cipriano River, Dagua River basin; Anchicayá, Aguaclara and Danubio Rivers, Anchicayá River basin, western slope of the Pacific versant, Valle del Cauca Department, Colombia (Fig. 7).
Natural history.This species is found in undisturbed clear and shallow rivers in strong current and on gravel to small stone substrates (riffles or runs).Cruciglanis pacifici generally shares its microhabitat with other species of fishes like Gobiesox sp., Chaetostoma marginatum, Cordilancistrus daguae, Astroblepus trifasciatus, Trichomycterus taenia; as well as shrimps (Atya).The stomach contents of five specimens caught in the Aguaclara River, showed immature aquatic insects belonging to Trichoptera, Diptera, Ephemeroptera and Odonata, and terrestrial insects of the orders Hymenoptera and Coleoptera.
The other synapomorphy described as spoon-like autopalatine with a roundish, dorso-ventrally expanded posterior tip, is corroborated as observed in all the available ma-  terial, in consequence six of the seven synapomorphies proposed are confirmed for the family Pseudopimelodidae, nevertheless, it is necessary to test these in all the members, including new characters and taxa (e.g., Shibatta, Lehmann & Reis, in progress); in order to establish a "well" supported phylogeny of pseudopimelodid genera.Additionally, Cruciglanis is distinguished from Cephalosilurus and Lophiosilurus, by the maxillary bone with a rounded border, ramified gill rakers, and depressed body (Shibatta, 2003b: 396), also Lophiosilurus has a second cartilaginous basibranchial (see Britto, 2002: fig. 48) which probably represents an autapomorphy for this genus; Microglanis, differs from Cruciglanis by its small adult size, premaxilla without a markedly developed postero-lateral projection, absence of vomer (Fig. 3d) and pectoral fin with 5 or 6 soft rays; Batrochoglanis is distinguished from the new genus by the absent of the vomer (Fig. 3c), supraoccipital process not contacting anterior nuchal plate (Fig. 4d), metapterygoid with ectopterygoideus process highly developed, levator arcus palatini crest slightly developed and caudal fin emarginated or rounded with longer dorsal lobe (Fig. 5c).
Cruciglanis, has a thick skin that covers the serrae of the anterior edge of the pectoral spine, a character proposed as autapomorphic for the genus Pseudopimelodus (Shibatta, 2003b); additionally it shares the following characters: supraoccipital in contact with the nuchal plate, posterior region of the supraoccipital process V-shaped (Fig. 4a-b); presence of seven rays in the pectoral fin and anterior nostril placed posterior to the maxillary barbel rim.
When the two genera are contrasted it is evidenced that Pseudopimelodus does not have an ectopterygoid process on the metapterygoid; the levator arcus palatini crest is well developed; possesses a conspicuous vomer articulated with the mesethmoid, lateral ethmoid and parasphenoid (Fig. 3b); also it presents an axilary pore and bifurcated caudal fin with equal lobes equal in size (Fig. 5b).Consequently, the presence of a depressed triangular mesocoracoid arch (Shibatta, 2003b: 395), is identified an autapomorphy for Pseudopimelodus.
Among the Pseudopimelodidae, Batrochoglanis and Microglanis share the absence of axillary pore (Shibatta & Pavanelli, 2005), a synapomorphic character proposed for these two genera by Shibatta (2003a), however, this character is also shared by Cruciglanis.
Cruciglanis, presents three basibranchial elements; the second and third brasibranchial are ossified, and the fourth basibranchial element is cartilaginous; according to de Pinna (1989de Pinna ( , 1993) ) the first basibranchial element is absent in all the Siluriformes, thus the first bony element present in this new taxon corresponds to the second basibranchial (bb 2 ) present in the other Otophysi.The second basibranchial reported here is cross shaped, id est with two lateral processes.This is not a unique condition among catfishes.De Pinna (1989), used the presence of a cross-shaped basibranchial element as a diagnostic character for Stauroglanis, a monotypic genus of trichomycterid.This shape and disposition according to the author op.cit., can be attributed to a marked modification of the second basibranchial (the third basibranchial is absent), or because of the possible fusion of this element with a second primitive basibranchial and a third basibranchial (considering the first basibranchial absent among the catfishes).Nevertheless, Stauroglanis (by de Pinna, 1989: 14, fig. 9) presents this unique basibranchial bony element articulating to a cartilaginous area with the first hypobranchial (hb 1 ), and its lateral processes articulate with the second hipobranchial (hb 2 ).The same does not occurr in Cruciglanis, where the anterior part of the second basibranchial (bb 2 ) is projected anteriorly in relation to the first hypobranchial, and the lateral processes of the second basibranchial (bb 2 ) articulates with the first hypobranchial (Fig. 2).In ligh of the above, and not detecting any suture indicating fusion of two basibranchial elements; we consider the similarities between the cruciform basibranchials of Stauroglanis and Cruciglanis, to be independent derived character states.
Adding Cruciglanis to the matrix of Shibatta (Table 1, 1998) and including the six autapomorphic characters proposed for the new genus [characters 56-61, Table 3], the phylogenetic analysis of these 61 characters resulted in eight equally parsimonious trees (length 112 steps, CI = 0.66, and RI = 0.78) .The strict consensus of these trees resulted in a cladogram (Fig. 8) with a length of the 114 steps, CI = 0.66, and RI = 0.77; where Cruciglanis form the sister group to Batrochoglanis and Microglanis.This three-genera clade is supported by seven synapomorphies [4, 9, 38, 44, 45, 46, and 53].In contrast with Shibatta (1998Shibatta ( , 2003b)), the genus Cephalosilurus and Lophiosilurus form the basal clade supported by five synapomorphies [characters 4, 23, 25, 39 and 44] among all other Pseudopimelodines and appears as the sister group to all the others genera.The monophyly of the genus Pseudopimelodus is supported by two unreversal characters [14 and 37].
The present cladistic reanalysis did not include two terminal taxa named "new genus" by Shibatta (1998: fig. 17) but, on the other hand, includes six additional characters and one additional terminal taxon.The tree length (114 steps) and the consistency index (0.66) of the present analysis differ from those found by Shibatta [55 characters,16 terminal taxa] us- ing Hennig86 computer program (Farris, 1988) and resulting in a strict consensus with 122 steps, CI = 0.58, and RI = 0.77.Therefore, a new arrangement is proposed by the relationships among genera of the Pseudopimelodidae (Fig. 8).

Diagnosis.
The new genus Cruciglanis, is distinguished from all other pseudopimelodid genera by the following characters: the subdorsal and the subadipose spots are joined forming an oval-shaped clear spot (Fig. 1, Character 56); the second basibranchial ossified, cross-shaped with lateral processes (Fig. 2, Character 57); ectopterygoid bone with the

Table 3 .
Shibatta (1998)es of Cruciglanis pacifici, for 55 characters presented byShibatta (1998)plus six additional characters included in the reanalysis (56-61).Characters are listed from top to bottom, arranged in separate groups in columns.