Taxonomy & naming
Parotocinclus arandai was described in 2009 by Luisa M. Sarmento-Soares, Pablo Lehmann A. and Ronaldo Martins-Pinheiro in Neotropical Ichthyology (volume 7, number 2, pages 191-198). The Catalog of Fishes (Eschmeyer, CAS) confirms it as a valid name (species id 70962).
The genus Parotocinclus is placed in the subfamily Hypoptopomatinae, the group of small armoured 'dwarf suckermouth' loricariids. The describing authors diagnosed P. arandai by a set of characters: the absence of a triangular dark patch at the anterior dorsal-fin base; a tuft of hypertrophied odontodes on the supraoccipital; an extensively naked abdomen in adults, with a mosaic of a few rounded platelets over the pre-anal region; a rostral plate that is not exposed ventrally; and a body depth of 16.1-18.6% of standard length.
Morphology
Parotocinclus arandai is a small loricariid, reaching about 1.5 in in standard length in the male and unsexed material examined. The body is relatively slender, with body depth measured at 16.1-18.6% of standard length. Meristic counts are one dorsal-fin spine and seven dorsal soft rays, six anal soft rays, and 22 vertebrae.
Distinctive features include a tuft of hypertrophied odontodes on the supraoccipital and, in adults, an extensively naked abdomen broken only by a mosaic of a few rounded platelets over the pre-anal region. The rostral plate is not exposed on the ventral surface, and there is no triangular dark patch at the anterior base of the dorsal fin — a useful mark for separating it from congeners. No sexual dimorphism is described in the available data.
Habitat
The species is endemic to Atlantic coastal drainages of eastern Brazil, recorded from tributaries of the middle and upper Rio Jucuruçu and the upper Rio Buranhém, across the states of Bahia and Minas Gerais. It is found in clear, shallow water — roughly 1 ft deep — in moderate river stretches with sandy or gravel bottoms.
Like other members of its genus, Parotocinclus is a facultative air-breather, able to gulp atmospheric air, which helps these small fishes cope with the warm, sometimes oxygen-poor conditions of shallow tropical shallows.
Feeding
No direct dietary analysis of Parotocinclus arandai has been published. As a small Hypoptopomatinae of sunlit, shallow, sand- and gravel-bottomed streams, it is expected to graze the aufwuchs — the film of algae, diatoms, and associated micro-organisms — that grows on substrate and submerged surfaces, but specific stomach-content data are not available.
Mating
No data on courtship or mating behaviour have been published for this species.
Breeding
No data on reproduction, spawning mode, clutch size, or parental care have been published for Parotocinclus arandai. No reproductive details should be inferred from related species.
In the aquarium
Parotocinclus arandai is not an established aquarium-trade species, and no published husbandry information exists for it specifically. While some Parotocinclus species do appear in the hobby as peaceful algae-grazers, the care of this particular species is undocumented, and any guidance would be speculative.
Conservation
The IUCN Red List assessed Parotocinclus arandai as Least Concern (LC), with the assessment dated 7 November 2018. Despite its restricted range in the Jucuruçu and Buranhém drainages of eastern Brazil, the species is not currently considered at elevated risk. As with other narrow-range fishes of Atlantic coastal streams, its long-term security depends on the condition of those drainages, but no specific threats are noted in the available assessment record.