Aspidoras raimundi (Steindachner, 1907)

Tencatt, Luiz Fernando Caserta, Britto, Marcelo R., Isbrücker, Isaäc Jan Hendrik & Pavanelli, Carla Simone, 2022, Taxonomy of the armored catfish genus Aspidoras (Siluriformes: Callichthyidae) revisited, with the description of a new species, Neotropical Ichthyology (e 220040) 20 (3), pp. 1-159 : 122-136

Aspidoras raimundi (Steindachner, 1907)

( Fig. 63 )

Corydoras raimundi Steindachner, 1907: 84 (original description; type locality: at mouth of brook emptying into Parnahyba [= Parnaíba ] River near Victoria [ Alto Parnaíba ], Maranhão State, Brazil). — Eigenmann , 1910: 403 (listed). — Regan , 1912: 215 (identification key; description, after Steindachner , 1907). — Ellis , 1913: 409 (identification key; listed). — Gosline , 1940: 21 (identification key; listed). — Gosline , 1945: 75 (listed). — Fowler, 1954: 66 (listed). — Nijssen, 1970: 58 (listed as a member of the “ Corydoras barbatus group ”).

Aspidoras raimundi (Steindachner, 1907) :—Nijssen, Isbrücker, 1976: 111 (transferred to Aspidoras ; identification key; designation of the lectotype; redescription). — Lima, Britto, 2001: 1015 (listed as comparative material). —Reis, 2003: 292 (listed). —Ferraris, 2007: 110 (listed). —Oliveira et al., 2017: e160118[3] (morphological comparison). —Tencatt, Bichuette, 2017: 8 (morphological comparison).

Aspidoras menezesi Nijssen & Isbrücker, 1976:120 (original description; type locality: Granjeiro River at Crato , Ceará State, Brazil; new synonym). — Reis , 2003:292 (listed). — Ferraris , 2007:109 (listed). — Oliveira et al., 2017:e160118[3] (morphological comparison; partim). — Tencatt, Bichuette, 2017:8 (morphological comparison).

Aspidoras aff. menezesi (Nijssen & Isbrücker, 1976) : — Britto, 2000:1054 (listed as comparative material). — Lima, Britto, 2001:1015 (listed as comparative material).

Aspidoras spilotus Nijssen & Isbrücker, 1976:123 (original description; type locality: dos Macacos Stream, tributary to the Acaraú River, Ceará State, Brazil; new synonym). — Britto, 1998:361 (listed as comparative material). — Britto, 2000:1054 (listed as comparative material). —Leão et al., 2015:586 (listed as comparative material). —Reis, 2003:292 (listed). —Ferraris, 2007:110 (listed). —Oliveira et al., 2017:e160118[3] (morphological comparison). —Tencatt, Bichuette, 2017:8 (morphological comparison).

Diagnosis. Aspidoras raimundi can be distinguished from its congeners, with the exception of A. belenos , A. fuscoguttatus , A. kiriri , A. maculosus , A. mephisto , and A. poecilus , by having inner laminar expansion of infraorbital 1 moderately developed (vs. ranging from well developed to extremely well developed in A. albater and A. aldebaran ; well developed in A. azaghal and A. depinnai ; extremely well developed in A. gabrieli and A. lakoi ; poorly developed in A. psammatides and A. velites ); from A. kiriri by the absence of dark brown or black blotches on dorso- and ventrolateral body plates fused with flank midline blotches (vs. presence); it can be distinguished from A. mephisto by having a narrow frontal bone, with width slightly smaller than half of entire length (vs. relatively wide, with width equal to or slightly larger than half of entire length); it can be distinguished from A. belenos by having the following combination of features: large and intensely pigmented dark brown or black blotch on dorsal fin generally present (vs. absent), parapophysis of complex vertebra generally moderately developed (vs. well developed), and markings on ventrolateral body plates, when present, clearly scarcer, not considering the number of blotches in the series along flank midline (vs. markings generally present and clearly more numerous); from A. maculosus and A. poecilus it differs by having the following combination of features: dorsal fin generally lacking small dark brown or black spots (vs. always present in A. maculosus ; generally present in A. poecilus ), and dark brown or black markings on ventrolateral body plates, when present, scarcer, not considering the number of blotches in the series along flank midline (vs. markings generally present and more numerous).

Description. Morphometric data presented in Tab. 9. Head compressed with convex dorsal profile; somewhat triangular or trapezoid in dorsal view. Snout ranging from short to relatively well developed, and from rounded to pointed. Head profile convex from tip of snout to anterior nares; region of mesethmoid, frontal and/or parieto-supraoccipital slightly concave in some specimens; ascending slightly convex to nearly straight from this point to dorsal-fin origin. Profile slightly convex along dorsal-fin base. Postdorsal-fin body profile slightly concave or nearly straight to adipose-fin spine; slightly concave from this point to caudal-fin base. Ventral profile of body slightly convex from isthmus to pelvic-fin origin; region of gill opening slightly concave in some specimens; nearly straight from this point to anal-fin origin; slightly concave until caudal-fin base. Body roughly elliptical in cross section at pectoral girdle, gradually becoming more compressed toward caudal fin.

Eye rounded, located dorso-laterally on head; orbit delimited dorsally by lateral ethmoid, frontal and sphenotic, ventrally by infraorbitals. Anterior and posterior nares close to each other, only separated by flap of skin. Anterior naris tubular. Posterior naris close to anterodorsal margin of orbit, separated from it by distance ranging from slightly smaller to slightly larger than naris diameter. Mouth small, subterminal, width larger than bony orbit diameter. Maxillary barbel moderate to large in size, ranging from not reaching to surpassing anteroventral limit of gill opening. Outer mental barbel slightly larger than maxillary barbel. Inner mental barbel fleshy, with base close to its counterpart. Lower lip moderately developed, forming small semicircular or triangular fleshy flap; with two triangular fleshy flaps in some specimens. Small rounded papillae covering entire surface of all barbels, upper and lower lips, snout and isthmus.

Mesethmoid short; anterior tip ranging from short, slightly smaller than 50% of entire bone length, to long, slightly larger than 50% of entire bone length; posterior portion wide, generally entirely covered by thick layer of skin; small portions exposed in some specimens. Nasal slender, curved laterally, inner margin with poorly- to moderately-developed laminar expansion; outer margin generally with reduced laminar expansion; variably more developed; mesial border generally contacting only frontal; contacting frontal and mesethmoid in some specimens.

Frontal elongated, narrow, with width slightly smaller than half of entire length ( Fig. 3A ); anterior projection ranging from short, with size slightly smaller than nasal length, to long, with size larger than nasal length; anterior margin partially or entirely covered by thick layer of skin. Frontal fontanel relatively small, ellipsoid or somewhat rhomboid; posterior tip extension not entering anterior margin of parieto-supraoccipital. Sphenotic somewhat trapezoid, contacting parieto-supraoccipital dorsally, pterotic-extrascapular posteriorly, second infraorbital ventrally and frontal anteriorly. Pterotic-extrascapular roughly pipe-shaped, with posteriormost portion contacting first lateral-line ossicle, and ventral margin contacting opercle and cleithrum; posterior expansion almost entirely covering lateral opening of swimbladder capsule, leaving slender pseudotympanic area on its dorsal margin covered only by thick layer of skin. Parieto-supraoccipital wide, posterior process ranging from poorly developed to moderately developed; not contacting nuchal plate. Parieto-supraoccipital medial keel expanded ventrally; laminar, with posterior portion at same level as posterior process tip; posterior portion variably not reaching tip of posterior process; or expanded posteriorly, slightly surpassing tip of posterior process. Parieto-supraoccipital fontanel small, roundish; located medially on parieto-supraoccipital; fontanel occluded, reduced to a small fossa, in some specimens.

Two laminar infraorbitals with minute odontodes; infraorbital 1 large, ventral laminar expansion ranging from moderately to strongly well developed; anterior portion with laminar expansion ranging from moderately developed, reaching middle of nasal capsule, to extremely well developed, reaching anterior margin of nasal capsule ( Fig. 64 ); inner laminar expansion moderately developed ( Fig. 5C ); small portions of external surface covered by thick layer of skin; infraorbital 2 small, slender; with posterior laminar expansion generally poorly developed; strongly reduced in some specimens; inner laminar expansion moderately developed; posteroventral margin contacting posterodorsal ridge of hyomandibula; or close but not directly contacting; dorsal tip contacting only sphenotic; small portions of external surface covered by thick layer of skin ( Fig. 64 ). Posterodorsal ridge of hyomandibula, close to its articulation with opercle, oblong, relatively slender; exposed; dorsal ridge of hyomandibula, between pterotic-extrascapular and opercle, generally covered by thick layer of skin, not externally visible; or covered by relatively thick layer of skin, externally visible; or covered by thin layer of skin, exposed; exposed areas generally bearing small odontodes. Interopercle with posterior portion generally exposed; somewhat triangular, anterior projection generally moderately developed; relatively well developed in some specimens. Preopercle relatively slender, elongated, minute odontodes sparse on external surface. Opercle compact in shape, width larger than half of its length; free margin convex; posterodorsal region variably with smoothly concave area; without serrations and covered by small odontodes; some portions of bony distal margin irregular in some specimens.

Four branchiostegal rays decreasing in size posteriorly. Hypobranchial 2 somewhat triangular, tip ossified and directed towards anterior portion, posterior margin cartilaginous; ossified portion generally well developed, about twice size of cartilaginous portion; strongly developed, about triple size of cartilaginous portion in some specimens. Five ceratobranchials with expansions increasing posteriorly; ceratobranchial 1 with small process on anterior margin of mesial portion; process strongly reduced in some specimens; ceratobranchial 3 generally with continuous postero-lateral margin; variably notched; ceratobranchial 5 toothed on postero-dorsal surface, 21 to 35(18) teeth aligned in one row. Four epibranchials with similar size; epibranchial 2 slightly larger than others, with small pointed process on laminar expansion of posterior margin; process strongly reduced in some specimens; epibranchial 3 with triangular uncinate process on laminar expansion of posterior margin. Two wide pharyngobranchials (3 and 4), pharyngobranchial 3 with triangular laminar expansion on posterior margin; triangular laminar expansion variably with notches; two triangular expansions in some specimens. Upper tooth plate oval, with 25 to 46(18) teeth generally aligned in two rows on postero-ventral surface; aligned in three rows in some specimens.

Lateral-line canal entering neurocranium through pterotic-extrascapular, branching twice before entering sphenotic: pterotic branch with single pore; preoperculomandibular branch conspicuously reduced, with single pore opening close to postotic main canal; more developed, with pore opening closer to anteroventral border of pterotic-extrascapular in some specimens; postotic main canal widens just posterior to pterotic branch. Sensory canal continuing through pterotic-extrascapular, entering sphenotic as temporal canal, which splits into two branches: one branch giving rise to infraorbital canal, another branch entering frontal through supraorbital canal, both with single pore. Supraorbital canal branched, running through nasal bone. Epiphyseal branch of supraorbital canal relatively long, with pore opening close to frontal fontanel; or slightly shorter, with pore opening closer to supraorbital main canal. Nasal canal generally with three openings, first on posterior edge, second on posterolateral portion and third on anterior edge; second pore generally fused with first pore; second opening variably absent. Infraorbital canal running through entire second infraorbital, extending to infraorbital 1 and generally opening into two pores. Preoperculomandibular branch giving rise to preoperculo-mandibular canal, which runs through entire preopercle with three openings, leading to pores 3, 4, and 5, respectively; pore 3 opening at posterodorsal ridge of hyomandibula in some specimens.

Dorsal fin somewhat triangular, located just posterior to third dorsolateral body plate. Dorsal-fin rays II,6 (1), II,8 (62), posterior margin of dorsal-fin spine smooth. Nuchal plate poorly to moderately developed in length; posterior portion exposed and with minute odontodes; anterior tip covered by thick layer of skin; almost entirely exposed in some specimens ( Fig. 65 ); spinelet short; partially exposed; spine ranging from poorly developed, with adpressed distal tip reaching middle portion of dorsal-fin base, to relatively well developed, with adpressed distal tip slightly surpassing posterior origin of dorsal-fin base; anterior margin with small odontodes. Pectoral fin roughly triangular, its origin just posterior to gill opening. Pectoral-fin rays I,8(18), I,9(42), I,10(3); posterior margin of pectoral spine with 12 to 29 poorly- to well-developed serrations along almost its entire length; small region just posterior to origin of spine lacking serrations; some serrations directed towards origin of spine, perpendicularly directed or directed towards tip of spine; presence of bifid serrations in some specimens; base of branched rays with small laminar expansions on inner margin, generally more evident on first rays; laminar expansions variably with irregular margins ( Fig. 66 ). Anteroventral portion of cleithrum partially exposed; posterolateral portion of scapulocoracoid reduced, externally visible. Pelvic fin oblong, located just below third or fourth ventrolateral body plate, and at vertical through second or third dorsal-fin branched ray. Pelvic-fin rays i,5(62), i,6(1). Adipose fin roughly triangular, separated from posterior origin of dorsal-fin base by seven to eight dorsolateral body plates. Anal fin somewhat triangular, located just posterior to 12 th, 13 th, or 14 th ventrolateral body plates, and at vertical through region of preadipose platelets or origin of adipose spine. Anal-fin rays ii,4,i(2), ii,5,i(27), ii,6(34). Caudal-fin rays i,11,i(1), i,12,i(61), i,13,i(1), four to six dorsal and/or ventral procurrent rays; caudal fin bilobed, lobes with similar size; or dorsal lobe slightly larger than ventral lobe.

Two to four laterosensory canals on trunk; first ossicle tubular, second ossicle laminar, third and fourth lateral-line canals, if present, encased in third and fourth dorsolateral body plates, respectively. Body plates with conspicuous line of relatively large odontodes confined to posterior margins; dorsolateral body plates 24(4), 25(33), 26(24), 27(2); ventrolateral body plates 21(3), 22(27), 23(29), 24(4); dorsolateral body plates along dorsal-fin base 5(1), 6(51), 7(11); dorsolateral body plates between adipose-fin spine and caudal-fin base 7(6), 8(35), 9(22); preadipose platelets 2(4), 3(21), 4(34), 5(4); small platelets covering base of caudal-fin rays; small platelets disposed dorsally and ventrally between junctions of lateral plates on posterior portion of caudal peduncle.

Anterior margin of orbit, above region of junction of frontal with lateral ethmoid, generally with small platelets. Ventrolateral portion of snout, region of nasal capsule and dorsal portion of snout, above mesethmoid, variably with small platelets; ventrolateral portion of snout with relatively large platelets in some specimens. Region between nuchal plate and posterior process of parieto-supraoccipital with small- to medium-sized platelets in some specimens ( Fig. 65B ). Ventral surface of trunk covered by small irregular platelets, generally more concentrated on its anterior portion; platelets densely disposed in some specimens.

Vertebral count 23(5), 24(13), 25(1); ribs 6(14), 7(5) first pair conspicuously large; parapophysis of complex vertebra generally moderately developed ( Fig. 8C ); single specimen (UFPB 9418, CS, 23.0 mm SL) with well developed parapophysis on the right side of the body ( Fig. 8A ).

Coloration in alcohol. Color pattern highly variable. Ground color of body light or brownish yellow, with top of head dark brown. Posterodorsal portion of head, region below eye, opercle and cleithrum with scattered dark brown or black chromatophores;

variably with relatively large rounded or irregular black blotches on top of head. Snout covered by dark brown or black chromatophores on its dorsal surface; chromatophores densely disposed in some specimens; variably forming dark brown or black rounded, striated or irregular small to relatively large spots; spots diffuse in some specimens; generally, with dark brown or black diffuse or conspicuous stripe from anteroventral portion of orbit to upper lip lateral area; ventrolateral portion of snout with dark brown or black chromatophores in some specimens. Upper lip and maxillary barbel with dark brown or black chromatophores; area of lateral portion of upper lip with conspicuous concentration of dark brown or black chromatophores in some specimens; outer mental barbel generally lacking chromatophores. Dorsal series of four to six dark brown or black blotches, first on anterior portion of dorsal-fin base, second on posterior portion of dorsal-fin base, third, if present, between dorsal and adipose fins, fourth on adipose-fin base, fifth, if present, on middle portion of caudal peduncle, and sixth on caudal-fin base; blotches variably diffuse. Dorsal portion of body with conspicuous concentration of dark brown or black chromatophores between counterparts of dorsolateral body plates in some specimens. Ventral surface of trunk and region posterior to urogenital opening generally lacking chromatophores. First dorsolateral body plate with conspicuous concentration of dark brown or black chromatophores; posterior margin of some dorso- and ventrolateral plates, and lateral line pores with conspicuous concentration of dark brown or black chromatophores in some specimens. Midline of flank generally with longitudinal series of four to six small- to large-sized conspicuous dark brown or black blotches; blotches rounded, oblong or irregular; blotches variably diffuse or fused with each other, forming longitudinal stripe. Dorsal half of dorsolateral body plates with dark brown or black chromatophores; region of anterior and posterior portions of dorsal-fin base, between dorsal and adipose fins, adipose-fin base, and base of caudal peduncle generally with more concentrated chromatophores, forming conspicuous blotches in some specimens. Ventral half of dorsolateral body plates and dorsal half of ventrolateral body plates with concentration of dark brown or black chromatophores, forming conspicuous blotches in some specimens; blotches generally more evident on anterior portion of body and on area of flank midline blotches. Mid-ventral portion and ventral half of ventrolateral body plates generally with scarse dark brown or black chromatophores; almost entirely lacking chromatophores in some specimens; or mid-ventral portion of ventrolateral body plates on area of flank midline blotches with concentration of dark brown or black chromatophores, forming conspicuous blotches in some specimens; blotches generally more evident posteriorly to pelvic-fin origin; ventral portion of ventrolateral body plates with concentration of dark brown or black chromatophores, generally more evident posterior to anal-fin anterior origin, in some specimens. Dorsal fin generally lacking small spots, with conspicuous concentration of dark brown or black chromatophores on its middle portion, forming conspicuous, large to extremely large and intensely pigmented black blotch; blotch gradually becoming faded posteriorly in some specimens; area with concentration of dark brown or black chromatophores extending towards anterior portion of dorsal-fin base and/or towards distal margin of dorsal-fin in some specimens; remaining portions of dorsal fin generally with non-intensely pigmented chromatophores; blotch obliquely fragmented, forming two smaller blotches in some specimens; blotch(es) variably less pigmented; region of blotch(es) with almost entirely hyaline membranes in some specimens, forming series of dark brown or black spots; presence of non-aligned dark brown or black small spots in some specimens; dorsal-fin base with conspicuous concentration of dark brown or black chromatophores, generally more concentrated on bases of first and last branched rays; spine covered by dark brown or black chromatophores. Pectoral fin with dark brown or black chromatophores on its dorsal surface, generally more evident on spine and first branched rays; covered by dark brown or black spots in some specimens; spots generally diffuse and more evident on first branched rays; almost entirely hyaline in some specimens; region of body around dorsal portion of pectoral-fin origin variably with concentration of dark brown or black chromatophores. Pelvic fin generally entirely or almost entirely hyaline; with dark brown or black chromatophores on its dorsal surface in some specimens. Adipose-fin membrane with dark brown or black chromatophores; generally, with conspicuous concentration of dark brown or black chromatophores in some areas of membrane, more evident close to spine, forming isolated patches in some specimens; adipose-fin spine generally with dark brown or black chromatophores. Anal fin with conspicuous concentrations of dark brown or black chromatophores in some areas, generally more evident on its middle portion and bases of last branched rays; variably with one or two dark brown or black blotches; or hyaline. Middle portion of caudal-fin base, posteriorly to last flank midline blotch, generally with small- to medium-sized dark brown or black blotch; blotch diffuse or fused with last midlateral blotch in some specimens. Caudal fin with three to six transversal dark brown or black slender to wide bars.

Coloration in life. Similar to that observed in preserved specimens but with ground color of body grayish yellow in some specimens. Body covered by whitish yellow and green iridescent coloration ( Fig. 67 ).

Geographical distribution. Aspidoras raimundi is known from the rio Parnaíba basin in Ceará, Maranhão and Piauí states, rio São Francisco basin in Pernambuco State, rio Tocantins basin in Tocantins State, and from the rivers Acaraú, Coreaú and Jaguaribe basins in Ceará State, Brazil ( Fig. 55 ) .

Conservation status. Aspidoras raimundi is a widespread species, occurring in North and Northeast Brazil within the territories of Ceará, Maranhão, Pernambuco, Piauí and Tocantins states. Additionally , no threat to the species is currently known. According to the International Union for Conservation of Nature ( IUCN) categories and criteria (IUCN Standards and Petitions Subcommittee, 2019), Aspidoras raimundi can be classified as Least Concern (LC).

Remarks. After the analysis of high resolution photographs of the lectotype (NMW 61110) and paralectotypes (NMW 46792, 46794 and 46795), it was possible to observe at least four conspicuously variable features within the type series of A. raimundi : (I) the general morphology of snout, which ranged from short and rounded to moderately developed and pointed, (II) the size and intensity of pigmentation of the dorsal-fin blotch, ranging from large to extremely large and slightly faded to strongly pigmented, (III) the flank midline blotches, ranging from small to moderate in size and from roundish or irregular to longitudinally elongated, and (IV) the ventral laminar expansion of infraorbital 1, ranging from moderately to strongly well developed ( Fig. 64 ). Additionally, it was possible to observe the presence of a single juvenile specimen of Corydoras (possibly C. treitlii ) among the paralectotypes under voucher NMW 46795 ( Fig. 68 ), which must be properly identified and placed under a new voucher.

The analysis of non-type specimens from the rio Parnaíba basin revealed a slightly larger range of variation regarding color pattern, allowing the recognition of four morphotypes. Despite most specimens from the rio Parnaíba basin present a color pattern similar to the type specimens (e.g., UFPB 8159 , UFPB 9936 , UFPB 11012 , UFPB

11013, UFPB 11016, UFRN 3085, and UFRN 3346), some specimens lack conspicuous blotches along flank midline (UFPB 9934, in two of the eight examined; Fig. 69A ). In others, the flank midline blotches are fused with each other, forming larger longitudinally elongated blotches and/or stripe (UFPB 7072, in five of the seven examined, UFPB

9418, in 42 of the 43 examined, UFPB 9933, in three of the five examined, and in the single specimen of UFPB 11014; Fig. 69B ). The fourth morphotype has flank midline blotches fused with each other, forming larger longitudinally elongated blotches and/or stripe plus dorsal-fin blotch clearly less pigmented and/or fragmented, or even absent in some specimens (UFPB 9933, in two of the five examined, UFPB 9415, in 64 of the 67 examined, and in the two specimens of UFPB 11015; Fig. 69C ).

According to Nijssen, Isbrücker (1976:124), the color pattern of Aspidoras spilotus ( Fig. 70 ) is characterized by “Body with prominent dark brown, oval spots along the meeting of dorso- and ventrolateral body scutes. There are four more or less isolated spots in one paratype. In the other specimens the spots are united, sometimes forming a single longitudinal bar from cleithrum to base of caudal fin. Most of the specimens are intermediate between these two patterns.” and “Dorsal fin with small, dark brown spots, mostly in the upper half of the fin, sometimes forming one or two narrow horizontal or slightly oblique lines, irregularly arranged in other specimens, sometimes forming a small triangular blotch.”, which was also observed in several A. raimundi specimens. The analysis of photographs of the holotype (ZMA 112.284) and the examination of two paratypes (USNM 213568; Fig. 69D ), plus non-type specimens from the rio Acaraú basin, type locality of A. spilotus , revealed that the general morphological pattern, including infraorbitals, pectoral-fin spine serrations and distance between nuchal plate and posterior tip of parieto-supraoccipital process, also falls within the range observed in A. raimundi populations. Therefore, since no conspicuous diagnostic features were found, we propose the synonymyzation of A. spilotus with A. raimundi . Additionally, specimens from the rio Coreaú basin, Ceará State, also presented similar color and morphological patterns, with exception of the relatively large size of some specimens (UFPB 9247, with up to 39.3 mm SL; Fig. 69E ); these are also considered as a morphotype of A. raimundi .

The analysis of specimens from the rio Jaguaribe basin, Ceará State, from where A. menezesi ( Fig. 71 ) was described, also revealed that most of them present color and morphological patterns similar to those observed in the A. raimundi type specimens. However, some specimens present the variable dorsal-fin color patterns described by Nijssen, Isbrücker (1976:124) for A. spilotus , which are also present in some A. raimundi specimens examined herein. Despite Nijssen, Isbrücker (1976:121) did not mention the presence of a large blotch on dorsal fin, the analysis of photographs of the holotype showed that a large dark brown or black blotch is present, though irregular in shape ( Fig. 71 ). Considering the examined material, most specimens exhibit dorsal-fin pattern similar to that observed in typical A. raimundi , with only few specimens (MCP 47296, 3 of 14; MCP 47283, 1 of 15; and UFRN 1241, 3 of 3; Fig. 69F ) presenting the aforementioned variations found in A. raimundi populations. The frequency of the typical dorsal-fin color pattern was not counted in lots MZUSP 24634 and MZUSP 53430.

Regarding the series of blotches along midline of flank, Nijssen, Isbrücker (1976:120) mentioned that A. menezesi presents “Color pattern on sides of body variable, consisting of medium-sized to rather large irregular dark brown blotches, most prominent along midlateral longitudinal body scutes, posteriorly sometimes united to form one elongate horizontal blotch.”, and therefore overlapping with A. raimundi ( Fig. 69 ). Similar to what was observed in specimens previously attributed to A. spilotus from the rio Coreaú basin, the most different specimens in relation to A. raimundi are the unusually large ones (UFRN 1241, with up to 41.1 mm SL; Fig. 69F ). This is the case of the A. menezesi holotype (41.8 mm SL) and may have led Nijssen, Isbrücker (1976) to consider it as new. However, as the case of the populations from the rivers Acaraú and Coreaú basins, both previously recognized as A. spilotus , the most useful features to diagnose Aspidoras species (i.e., infraorbital 1, frontal and complex vertebra morphology and details in color pattern) were examined in several specimens matching the description of A. menezesi , and fell within A. raimundi range. Therefore, the most reasonable decision is to consider A. menezesi as a junior synonym of A. raimundi .

Additionally, a single specimen collected in a tributary to the rio São Francisco basin in Pernambuco State ( UFPB 7140 ; Fig. 69G ) and several specimens from the rio Tocantins basin in Maranhão and Tocantins states ( Fig. 69H ), strongly resemble A. raimundi in morphological and color patterns ( Fig. 69 ), presenting overlap in all potential diagnostic features raised in this study. For this reason, we consider them conspecific .

Currently, A. raimundi is one of the most common species of Aspidoras in the aquarium trade. Among the coded species, Aspidoras sp. C 125, with locality listed as “ Brazil ”, and CW119, with locality listed as “ Tocantins ”, clearly fit some of the variable forms of A. raimundi ( Figs. 69D–E for the patterns present in C125, and Figs. 69A,H for the patterns present in CW119).

Material examined. In addition to the material examined by Nijssen, Isbrücker (1976:120, 123), the following material was analysed. All from Brazil. Rio Parnaíba basin. UFPB 7072, 7 of 8, 19.9‒25.3 mm SL, Piauí, rio São Nicolau. UFPB 8159, 1, 25.6 mm SL, Piauí, rio Parnaíba. UFPB 9415, 67 of 176, 16.9‒26.6 mm SL, 2 CS of 176, 23.9‒24.2 mm SL, Ceará, rio Piau. UFPB 9418, 43 of 51, 16.0‒ 24.2 mm SL, 2 CS of 51, 21.0‒23.0 mm SL, Piauí, stream under the bridge on the road between São Miguel da Baixa Grande‒São Félix do Piauí. UFPB 9933, 5 of 6, 18.9‒23.1 mm SL, Ceará, rio Jaburu. UFPB 9934, 7 of 9, 22.0‒ 25.8 mm SL, 1 CS of 9, 22.4 mm SL, Maranhão, córrego Alagado. UFPB 9936, 2, 19.2‒19.5 mm SL, Piauí, rio Gurgueia. UFPB 11012, 5 of 6, 15.2‒24.3 mm SL, Piauí, rio Gurgueia. UFPB 11013, 6 of 7, 14.5‒19.2 mm SL, Piauí, córrego Bonfim. UFPB 11014, 1, 22.3 mm SL, Piauí, rio Sambito. UFPB 11015, 2, 21.2‒22.0 mm SL, Ceará, rio Arabé. UFPB 11016, 10 of 12, 12.2‒19.0 mm SL, 1 CS of 12, 21.2 mm SL, Maranhão, rio Parnaíba. UFRN 3085, 9, 13.7‒23.5 mm SL, Maranhão, rio Parnaíba. UFRN 3346, 20 of 43, 16.1‒23.0 mm SL, Piauí, rio Gurgueia. Rio Jaguaribe basin. MCP 47280, 2, 22.2‒23.5 mm SL, Ceará, rio Salgado. MCP 47283, 15 of 18, 21.3‒27.7 mm SL, 1 CS, 27.3 mm SL, Ceará, rio Batateiras. MCP 47284, 19 of 30, 19.5‒28.4 mm SL, 1 CS of 30, 25.2 mm SL, Ceará, rio Batateiras. MCP 47294, 7, 20.0‒23.0 mm SL, Ceará, rio Batateiras. MCP 47296, 14 of 20, 22.1‒29.2 mm SL, 1 CS of 20, 27.5 mm SL, Ceará, rio Salgado. MCP 47303, 9 of 16, 23.2‒28.8 mm SL, 1 CS of 16, 28.4 mm SL, Ceará, rio Batateiras. MCP 47304, 9 of 17, 21.3‒29.7 mm SL, 1 CS of 17, 28.3 mm SL, Ceará, rio Batateiras. MNRJ 42399, 1, 28.1 mm SL, Ceará, rio Salamanca. MNRJ 47929, 1, 30.0 mm SL, Ceará, rio Jaguaribe. MZUSP 24634, 29, 15.4–37.2 mm SL, Ceará, córrego Água Suja. MZUSP 53430, 15, 17.3–39.4 mm SL, Ceará, córrego Água Suja. UFPB 9427, 1, 24.4 mm SL, Ceará, rio Cascata. UFRN 1241, 3, 34.1‒41.1 mm SL, Ceará, córrego da Cascata. Rio Acaraú basin. MZUSP 110755, 7, 20.9‒43.1 mm SL, Ceará, weir in the rio Acaraú. MZUSP 110778, 1, 27.8 mm SL, Ceará, rio Acaraú. UFPB 7064, 20, 9.4‒25.1 mm SL, Ceará, rio Acaraú. UFPB 7616, 6, 18.2‒19.9 mm SL, Ceará, rio Groaíras. UFRN 2895, 1, 23.1 mm SL, Ceará, córrego Ipuçaba. UFRN 3735, 16, 19.7‒27.5 mm SL, Ceará, córrego Ipuçaba. UFRN 3745, 12, 22.3‒29.8 mm SL, Ceará, córrego Ipuçaba. R io Coreaú basin. UFPB 9247, 3 of 7, 34.3‒39.3 mm SL, 2 CS of 7, 27.4‒30.5 mm SL, Ceará, rio das Minas. UFPB 9251, 4, 22.2‒27.2 mm SL, Ceará, rio Ubajara. UFRN 1466, 3, 20.5‒31.5 mm SL, Ceará, córrego Gavião. UFRN 2662, 10, 19.4‒25.4 mm SL, Ceará, córrego Gavião. Rio São Francisco basin. UFPB 7140, 1, 22.2 mm SL, Pernambuco, córrego São Pedro. R io Tocantins basin. MNRJ 42401, 9, 19.8‒31.8 mm SL, Tocantins, córrego Suçuarana. MNRJ 49844, 59, 13.5‒28.4 mm SL, Maranhão, unnamed stream. UNT 539, 5 of 6, 24.7‒27.6 mm SL, 1 CS of 6, 25.1 mm SL, Tocantins, stream crossing the road BR 153 between Filadélfia and Araguaína, 79 km from Araguaína. UNT 7833, 3, 18.0‒ 20.3 mm SL, Tocantins, rio Palmas. UNT 10106, 11 of 13, 20.4‒36.0 mm SL, 2 CS of 13, 25.9‒28.3 mm SL, Tocantins, stream tributary to the rio Manuel Alves. UNT 10135, 7 of 8, 18.8‒28.5 mm SL, 1 CS of 8, 23.7 mm SL, Tocantins, stream tributary to the rio Manuel Alves. UNT 10136, 2, 18.3‒20.2 mm SL, Tocantins, stream tributary to the rio Manuel Alves. UNT 12295, 6 of 7, 18.5‒32.0 mm SL, 1 CS of 7, 28.4 mm SL, Tocantins, isolated ponds at Boa Fé Farm. UNT 12305, 10 of 11, 18.7‒34.0 mm SL, 1 CS of 11, 23.3 mm SL, Tocantins, córrego Cana Brava. UNT 14451, 1, 28.6 mm SL, Tocantins, rio Manuel Alves. UNT 14452, 5, 21.0‒ 28.5 mm SL, Tocantins, rio Manuel Alves. UNT 14465, 3, 23.1‒30.6 mm SL, Tocantins, rio Gameleira. UNT 14557, 3, 18.8‒20.4 mm SL, Tocantins, rio Arraias.

Figures

FIGURE 3 | Dorsal view of the head of CS specimens showing the three patterns of paired frontal bones (outlined in black) in Aspidoras: (A) narrow, with width of each frontal slightly smaller than half of its entire length (Aspidoras maculosus, UFBA 3291, 30.7 mm SL), (B) relatively wide, with width equal to or slightly larger than half of entire length (Aspidoras albater, MZUSP 40793, 29.4 mm SL), and (C) extremely narrow, with width clearly smaller than half of entire length (Aspidoras psammatides, UNT 9604, 27.3 mm SL). Scale bars = 1 mm.

FIGURE 5 | Dorsal view of the infraorbital series of CS specimens showing the four patterns of size and shape of the inner laminar expansion of infraorbital 1 (white arrows) in Aspidoras: (A) extremely well developed (Aspidoras albater, MNRJ 13080, 30.9 mm SL), (B) well developed (Aspidoras fuscoguttatus, NUP 12677, 36.1 mm SL), (C) moderately developed (Aspidoras poecilus, UNT 6249, 30.9 mm SL), and (D) poorly developed (Aspidoras psammatides, UNT 9604, 27.3 mm SL). Abbreviations: io1: infraorbital 1, io2: infraorbital 2. Scale bars = 1 mm.

FIGURE 8 | Ventral view of the complex vertebra in CS specimens of (A) Aspidoras belenos, paratype, UFRJ 4419 (ex-UFRJ 3861), 22.1 mm SL, with well-developed parapophysis, (B) Aspidoras albater, MNRJ 12571, 35.3 mm SL, with poorly-developed parapophysis, and (C) Aspidoras albater, MNRJ 12581 (disarticulated, indeterminate size), with moderately-developed parapophysis. Abbreviations: ccv: centrum of the complex vertebra, pcv: parapophysis of the complex vertebra. Scale bars = 1 mm.

FIGURE 55 | Map showing the geographical distribution of Aspidoras poecilus (type locality: red circle; non-type localities: black circles), A. psammatides (type locality: purple cross; non-type localities: white crosses), A. raimundi (type locality: red triangle; non-type localities: white triangles), A. rochai (type locality: red star), and A. velites (type locality: purple diamond; non-type localities: white diamonds). Each symbol may represent more than one locality.

FIGURE 63 | Aspidoras raimundi, lectotype, NMW 61110, 25.5 mm SL, mouth of a stream emptying into the rio Parnaíba near Victoria (Alto Parnaíba), Maranhão State, Brazil. Dorsal (top), lateral (middle) and ventral (bottom) views. Photos by Anja Palandacic.

FIGURE 64 | Lateral view of the head of CS specimens of Aspidoras raimundi, showing the infraorbitals patterns of the species. Ventral laminar expansion of infraorbital 1 moderately developed in (A) and (B) (UNT 10106, 28.3 mm SL and MCP 47296, 27.5 mm SL, respectively), and well developed in (C) and (D) (UFPB 9934, 22.4 mm SL and MCP 47283, 27.3 mm SL, respectively). Abbreviations: io1: infraorbital 1, io2: infraorbital 2, sph: sphenotic, pes: pterotic-extrascapular. Scale bars = 1 mm.

FIGURE 65 | Predorsal region of trunk in dorsal view in CS specimens of Aspidoras raimundi, showing the following morphological variation: nuchal plate (A) separated from the posterior process of the parieto-supraoccipital by the first and second dorsolateral body plates (UFPB 9934, 22.4 mm SL), and (B) nearly touching the posterior process of the parieto-supraoccipital, with platelets on the region between them (black arrows) (MCP 47283, 27.3 mm SL). Dotted lines indicate the limits of the tip of the posterior process of the parieto-supraoccipital and anterior tip of the nuchal plate. Abbreviations: np: nuchal plate, pso: parieto-supraoccipital. Scale bars = 1 mm.

FIGURE 66 | Dorsal view of pectoral fin in CS specimens of Aspidoras raimundi, showing variation in the morphology of pectoral-fin spine: (A) presence of simple and/or bifid poorly- developed serrations on its posterior margin (MCP 47283, 27.3 mm SL), or (B) with simple and/or bifid moderately- and/or well-developed serrations on its posterior margin (UFPB 9934, 22.4 mm SL). Arrows indicate the small laminar expansions at the base of branched rays. Scale bars = 1 mm.

FIGURE 67 | Uncatalogued aquarium specimens of Aspidoras raimundi photographed alive, showing variation in color pattern: (A) typical pattern, (B) typical pattern but densely mottled, (C) dorsal fin with diffuse blotch, midline blotches large, elongated and non-fused, (D) dorsal fin with diffuse blotch plus spots, midline blotches large and variably elongated, which may be fused, forming a longitudinal stripe, or (E) dorsal fin with with almost entirely hyaline membranes and spots roughly aligned in longitudinal rows, midline blotches large and variably elongated, which may be fused, forming a longitudinal stripe. Photos by Telton Ramos (A), Ingo Seidel (B) and Hans Evers (C–E).

FIGURE 68 | Corydoras specimen (19.0 mm SL) found within the type series of Aspidoras raimundi (NMW 46795).

FIGURE 69 | Specimens of Aspidoras raimundi showing general morphological and color patterns variations in lateral view; (A) UFPB 9934, 24.8 mm SL, (B) UFPB 9418, 24.2 mm SL, (C) UFPB 9415, 24.9 mm SL, (D) USNM 213568, paratype of Aspidoras spilotus, 22.7 mm SL, (E) UFPB 9247, 39.3 mm SL, (F) UFRN 1241, 41.1 mm SL, (G) UFPB 7140, 22.2 mm SL, and (H) UNT 14465, 29.4 mm SL. Photos (A) and (H) by Bruno Ferreira.

FIGURE 70 | Holotype of Aspidoras spilotus, junior synonym of Aspidoras raimundi, ZMA 113590, 34.0 mm SL, Riacho dos Macacos, Ceará State, Brazil. Dorsal (top), lateral (middle) and ventral (bottom) views. Photos by Mark Allen.

FIGURE 71 | Holotype of Aspidoras menezesi, junior synonym of Aspidoras raimundi, UMMZ 147336, 41.8 mm SL, tributary to the left bank of the rio Salgado, Brazil. Dorsal (top), lateral (middle) and ventral (bottom) views. Photos by Heok Hee Ng.