A new species of Parotocinclus with reduced adipose fin (Loricariidae: Hypoptopomatinae), from the rio Jacuípe basin, Bahia State, Brazil

Abstract

<jats:p>ABSTRACT A new species of Parotocinclus, apparently endemic to the rio Jacuípe basin, Bahia State, Brazil, is described. The new species is distinguished from congeners, except P. bidentatus, P. cabessadecuia, P. dani, P. halbothi, P. muriaensis, P. pentakelis, P. seridoensis, and P. spilurus, by the presence of a reduced adipose fin. The new species differs from the aforementioned species by the absence of unicuspid accessory teeth, abdomen with broad naked areas between lateral and medial patches of plates, and snout tip completely covered by plates and odontodes. The adipose fin of the new species is restrict solely to the adipose-fin spine, lacking the adipose-fin membrane, a reduction pattern previously described to P. halbothi, a congener from rivers of the Amazonas and Marowijne basins.</jats:p>

A new species ofParotocinclus(Loricariidae: Hypoptopomatinae) from the rio Pardo basin, Bahia State, Brazil, with comments on the sexually dimorphic traits of the nares and olfactory lamellae

“…Pelvic‐fin rays i, 5; tip of adpressed fin reaching anal‐fin origin in males and shorter, in females. Adipose‐fin vestigial, with a single plate replacing it (one c&s specimen), or rudimentary with elevation at typical adipose‐fin position formed by a series of two to three azygous plates (two c&s specimens) covered by odontodes (type 3 and 4 sensu Silva‐Junior et al ., 2020); from 70 alcohol preserved specimens examined to the feature, 48 (68.9%) possess a small elevation at typical adipose‐fin position (possibly the rudimentary condition described) and 22 (31.4%) do not have any trace of adipose fin visible externally (possibly the vestigial condition described). Anal‐fin rays i, 5.…”

“…Parotocinclus pukuixe is distinguished from congeners, except P. bidentatus Gauger & Buckup, P. cabessadecuia Ramos, Lima & Ramos, P. jacumirim , P. muriaensis Gauger & Buckup, P. seridoensis Ramos, Barros‐Neto, Britski & Lima, and occasionally P. spilurus (Fowler), by having a rudimentary or vestigial adipose fin ( vs . well‐developed adipose fin; following Silva‐Junior et al (2020:3) a rudimentary adipose fin means absence of spine and membrane but with a small ridge visible externally along adipose‐fin typical locality, and a vestigial fin means only one small plate replacing the adipose fin). The new species differs from P. bidentatus and P. muriaensis by the absence of unicuspid accessory teeth ( vs .…”

Rio de Janeiro and other palaeodrainages evidenced by the genetic structure of an Atlantic Forest catfish

“…Along the coastal landscape of southeastern Brazil, the CFML is the narrowest portion of the continental shelf (Figure 1), and the southeastern end of an intracontinental magmatic divide, which influenced the hydrological network rearrangements and the freshwater taxa distribution (Ribeiro et al, 2018). The influence of this barrier is reflected in the levels of endemism of the São João River basin (Costa, 2014;Roxo et al, 2017), or as a geographical divide with different species or lineages north or south of the lineament (Pereira et al, 2013;. The CFML as a strong biogeographical barrier for freshwater fish becomes evident by the geographical range of some species and by the deep genetic structure of T. aff.…”

Parotocinclus jacksoni, a new hypoptopomatine catfish (Siluriformes: Loricariidae) from the Rio Mamanguape basin, north‐eastern Brazil

“…The relationships between subfamily genera are controversial (Roxo et al ., 2019a): Parotocinclus is a genus with unclear taxonomic limits and is therefore considered paraphyletic within Hypoptopomatinae, even in the face of advances in morphological, molecular and genomic studies (Cramer et al ., 2011; Martins et al ., 2014; Roxo et al ., 2019a; Silva et al ., 2016). Parotocinclus is the most diverse genus of the subfamily, and in the last decade a total of 14 species were described, more than one species per year, encompassing 38 species of the genus (Fricke et al ., 2021; Lehmann et al ., 2020; Lehmann & Reis, 2012; Pereira et al ., 2019; Silva‐Junior et al ., 2020). Currently, 21 valid species are registered in freshwater ecoregions that drain the north‐east, approximately 56% of those described for the genus to date (Figure 1).…”

“…Currently, 21 valid species are registered in freshwater ecoregions that drain the north‐east, approximately 56% of those described for the genus to date (Figure 1). In the four ecoregions in the Caatinga domain of north‐eastern Brazil, six species have been described in the last decade: Parotocinclus cabessadecuia Ramos, Lima & Ramos, 2017 in the Maranhão‐Piauí ecoregion, P. seridoensis Ramos, Barros‐Neto, Britski & Lima, 2013 in the mid‐north‐eastern Caatinga ecoregion, P. robustus Lehmann & Reis, 2012 in the São Francisco ecoregion and four species in the north‐eastern Atlantic Forest, P. jequi Lehmann, Braun, Pereira & Reis, 2013, P. adamanteus Pereira et al ., 2019, P. jacumirim Silva‐Junior et al ., 2020 and Parotocinclus nandae Lehmann et al ., 2020 (Fricke et al ., 2021; Lima et al ., 2017). Among the species described, the only threatened species of the genus is Parotocinclus spilurus (Fowler, 1941), endemic to Caatinga, in the Rio Jaguaribe basin, Ceará State, assessed as Endangered following the IUCN criteria (ICMBio, 2018; Ramos et al ., 2016).…”