Parotocinclus haroldoi , Garavello 1988

Abstract

Parotocinclus haroldoi Garavello, 1988 Figs. 1–4, Tables 1–2 Parotocinclus haroldoi Garavello, 1988: 117–128, fig. 1. Type locality: Córrego do Otaviano, Poço do Sanharó, Riacho Sanharó, Piauí, Brazil (Otaviano stream, Sanharó pit, creek Sanharó, Piauí, Brazil)”, holotype MNRJ 10531. Parotocinclus haroldoi Garavello (1988): Lacerda & Evers (1996): 88, 92 (ilustration); Burgess & Finley (1996):170; Isbrücker (2001): 31 (literature compilation); Ribeiro et al. (2002): 218; Britski & Garavello (2002): 287 (literature compilation); Isbrücker (2002): 25 (literature compilation); Reis et al. (2003): 326 (checklist of species); Rosa et al. (2003) (list of species); Lehmann A. & Reis (2012):62 (literature compilation); Gauger & Buckup (2005): 517 (literature compilation); Ferraris, Jr. (2007): 282 (checklist and catalogue of species); Ramos et al. (2013): 788 (literature compilation); Ramos et al. (2014): 4; Ramos et al. (2016):10 (comparative material); Rodrigues-Filho et al. (2016): (new record); Lima et al. (2017): (literature compilation); Ramos et al. (2017):7 (comparative material); Berbel-Filho et al. (2018) (literature compilation). Diagnosis. Parotocinclus haroldoi is distinguished from all its congeners, except from P. amazonensis Garavello, P. aripuanensis Garavello, P. bidentatus Gauger & Buckup, P. britskii Boeseman, P. cabessadecuia Ramos, Lima & Ramos, P. collinsae Schmidt & Ferraris, P. cristatus Garavello, P. dani Roxo, Silva & Oliveira, P. jimi Garavello, P. longirostris Garavello, P. yaka Lehmann, Lima & Reis, P. maculicauda (Steindachner) P. muriaensis Gauger & Buckup, P. planicauda Garavello & Britski, P. polyochrus Schaefer, P. spilurus (Fowler) and P. variola Lehmann, Schvambach & Reis by having the abdomen entirely covered by plates between the pectoral girdle and preanal region (Figs. 1, 2 and 3), (vs. abdomen completely naked or abdomen nearly naked, with only one or two row of plates on each side and median row of platelets irregularly distributed). Parotocinclus haroldoi differs from P. amazonensis by having a higher number of teeth (26) (vs. less 16) and from P. longirostris and P. polyochrus by having a smaller number of teeth in the premaxillary and dentary (18–26) (vs.>31); from P. bidentatus, P. cabessadecuia, P. dani, P. muriaensis and P. spilurus by present presence of an adipose fin (vs. adipose fin rudimentary or absent); from P. cristatus and P. jimi by having the abdomen covered by relatively broad dermal plates (vs. covered by small dermal plates). Parotocinclus haroldoi differs from P. aripuanensis, P. britskii, P. collinsae, P. yaka, P. maculicauda, P. planicauda and P. variola by the presence of small bright spots on the head and the body, usually less than the eye diameter predominantly disposed in rows (vs. body without bright spots). Besides the presence of the spots, P. haroldoi differ from P. britskii and P. collinsae by having 24–26 lateral plates (vs. 21–23) and from P. planicauda and P. britskii by the presence of an abdomen covered by broad dermal plates forming 3–5 series longitudinal of plates (vs. covered by small dermal plates; 7–10 series longitudinal of plates). In addition Parotocinclus haroldoi differs from geographically close species, P. cabessadecuia, P. cesarpintoi, P. cearensis and P. spilosoma by the presence of small light spots on the head and trunk (vs. absence); from P. cabessadecuia, P. seridoensis and P. spilurus by present presence of an adipose fin (vs. adipose fin rudimentary or absent). Description. Morphometric and meristic data of topotypes are presented in Table 1 and 2, respectively (largest examined specimen 46.2 mm SL). Body slightly short and somewhat depressed. Greatest body width at cleithrum, progressively tapering to the end of caudal peduncle. Dorsal profile slightly convex from snout to dorsal-fin origin; slightly concave from dorsal-fin origin to adipose fin; straight at adipose fin base; slightly concave from this point to origin of uppermost caudal-fin rays. Ventral body profile of head straight or slightly concave; ventral profile of trunk somewhat convex from pectoral girdle to posterior base of pelvic fin; ventral profile of trunk somewhat convex from pectoral girdle to posterior base of pelvic fin; somewhat concave of the anus origin to lowermost caudal-fin rays. Head and snout depressed and rounded in dorsal view. Eyes relatively small, dorsolaterally positioned midway between snout tip and pterotic-supracleithrum anterior margin; distance between orbit margin and ventral surface of head greater than orbital diameter. Dorsal iris operculum present. Interorbital space slightly convex. Pectoral girdle completely exposed and covered by odontodes, except for small triangular anterior area over median suture where skin is visible in some specimens, arrector fossae small, almost meeting in at midline. Greatest body depth at dorsal-fin origin, inferior rostral margin of snout with posteriorly directed odontodes; odontodes on upper part of head, arranged in rows and similar in size those of the inferior rostral margin of snout. Oral disk ovate with numerous small papillae; maxillary barbels shorter than orbital diameter. All teeth short and bifid. Trunk depressed at insertion of dorsal and anal fin. Caudal peduncle rounded in cross section. Dorsal fin i,7; its origin immediately posterior to unbranched first ray of the pelvic-fin; other rays branched; dorsal fin when adpressed extending to vertical through beyond anal-fin base. Adipose fin present. Pectoral fin i,6; unbranched pectoral fin first ray, slightly curved, covered with small odontodes, reaching one quarter to one third of length of first pelvic-fin ray; other rays branched. Pelvic-fin rays i,5; unbranched first ray curved, covered with small odontodes; pelvic-fin reaching beyond anus, ending just anterior to anal-fin origin. Anal-fin i,5; base covering three plates. Caudal fin i,14,i; slightly notched, with lower lobe slightly longer than upper. Lateral-line canal in median series complete, pore tube visible. Abdomen completely covered of dermal plates between the pectoral girdle and the anus; with five to seven rows of elongate plates. Dorsal-fin spine flexible, with locking mechanism nonfunctional, followed by seven branched rays. Nuchal plate exposed, not covered by skin. Dorsal-fin spinelet present, V-shaped, wider than base of dorsal spine. Total vertebrae 21 (2 c&s). Coloration. Background color in ethanol of dorsal and lateral surfaces dark brown to grayish, with four lighter dark brown bars inconspicuous on the upper part of the trunk; most previous at the dorsal fin origin; the second on the base of the dorsal fin; the third at the adipose fin origin and the last on the caudal peduncle, near the origin of the caudal fin. Side with a dark brown band extending from the previous part or the snout to the caudal peduncle. Clear yellowish small elongated spots on the dorsal and lateral regions of the head and trunk, lighter patch in the pineal region; the spots of the trunk generally converging in two series on the lateral (Figs. 1, 2). Ventral region of the head and abdomen (trunk) yellowish. Fins with dark chromatophores concentrated, forming irregular set of stripes that alternates between dark brown and yellow clear: dorsal fin of three or four stripes; pectoral, pelvic and anal fins of two or three stripes dark brown inconspicuous. Caudal fin with three stripes dark, the first two rather dark: one transversal on the base of fin, the second a bar oblique only in the lower lobe and third transversal inconspicuous in both lobes. Coloration in life follows the same pattern described above, with the small elongated spots yellowish pattern more evident (Fig. 4). Distribution. Parotocinclus haroldoi is known from the Parnaíba river basin (Fig. 5). The Parnaíba river basin extends in Ceará, Piauí and Maranhão States, Northeast, Brazil, in Caatinga and Cerrado region. Parotocinclus haroldoi was collected at various locations in the upper, middle and low portions of the rio Parnaíba, suggesting a wide geographic distribution of the species within the basin, large portion of places under the Caatinga domain and a small portion of the high Parnaíba, in the Cerrado. Specimens were collected in the main course of the rio Parnaíba, and also on tributaries Gurgueia, Canindé-Piauí, Poti and Longá. In its original description, Garavello (1988) only mention the Córrego do Otaviano, Pocó do Sanharó, riacho Sanharó, Piauí as its type locality, not specifying the municipality. Sexual dimorphism. Males possess urogenital papilla positioned just behind anal opening. No other characters of sexual dimorphism were recorded in Parotocinclus haroldoi, as described for example for P. cabessadecuia in Ramos et al. (2017), Ecological notes. Parotocinclus haroldoi is usually found in moderate current flow in rivers with rock bottom and gravel substrate, at rivers under the dominion of the Caatinga and Cerrado. Parotocinclus haroldoi was registered in co-occurrence in rio Guaribas, tributary of Canindé-Piauí with other loricariids: Ancistrus damasceni (Steindachner), Loricariichthys derbyi Fowler, Hypostomus johnii (Steindachner) and Hypostomus sp. Other co-occuring species were Aequidens tetramerus (Heckel), Astyanax bimaculatus (Linnaeus), Astyanax fasciatus (Cuvier), Caenotropus labyrinthicus (Kner), Characidium zebra Eigenmann, Cichlasoma sanctifranciscense Kullander, Compsura heterura Eigenmann, Crenicichla menezesi Ploeg, Curimatella immaculata (Fernández-Yépez), Geophagus parnaibae Staeck & Schindler, Hemiodus parnaguae Eigenmann & Henn, Hoplias malabaricus (Bloch), Leporinus piau Lutken, Jupiaba polylepis (Günther), Knodus victoriae (Steindachner), Phenacogaster calverti (Fowl- er), Pimelodus sp., Poecilia sarrafae Bragança & Costa, Potamotrygon signata Garman, Prochilodus lacustris Steindachner, Psellogrammus kennedyi (Eigenmann), Pygocentrus nattereri Kner, Schizodon rostratus (Borodi