Friday, June 8, 2018

[Ichthyology • 2018] Hyphessobrycon piorskii • A New Species of Hyphessobrycon Durbin (Characiformes, Characidae) from northeastern Brazil: Evidence from Morphological Data and DNA Barcoding


Hyphessobrycon piorskii
 Guimarães, De Brito, Feitosa, Carvalho-Costa & Ottoni, 2018


Abstract
A new species of Hyphessobrycon is described for the upper Munim and Preguiças river basins, northeastern Brazil, supported by morphological and molecular species delimitation methods. This new species belongs to the Hyphessobrycon sensu stricto group, as it has the three main diagnostic character states of this assemblage: presence of a dark brown or black blotch on the dorsal fin, absence of a black midlateral stripe on its flank and the position of Weberian apparatus upward horizontal through dorsal margin of operculum. Our phylogenetic analysis also supported the allocation of the new species in this group; however, it was not possible to recover the species sister-group. Pristella maxillaris and Moenkhausia hemigrammoides were recovered as the sister-clade of the Hyphessobrycon sensu stricto group.

Keywords: Hyphessobrycon sensu stricto, integrative taxonomy, Pristellinae, rosy tetra clade


Figure 2. Hyphessobrycon piorskii sp. n. A CICCAA 00698, paratype, 26.9 mm SL, Brazil: Maranhão State: Munim River basin; living specimen photographed immediately after collection
B CICCAA 00089, paratype, 25.2 mm SL, Brazil: Maranhão State: Munim River basin; living specimen photographed immediately after collection (photographed by Felipe Ottoni).

Hyphessobrycon piorskii sp. n.
  
Diagnosis: 
(PAA). The new species Hyphessobrycon piorskii sp. n., promptly differs from most congeners except by species of Hyphessobrycon sensu stricto by the presence of a dark brown or black blotch on dorsal fin (vs. absence), no midlateral stripe on the body (vs. presence) and Weberian apparatus upward horizontal through dorsal margin of operculum (vs. downward).

The new species herein described differs from all of its congeners from Hyphessobrycon sensu stricto, with exception to H. bentosi and H. hasemani, by possessing an inconspicuous vertically elongated humeral spot [vs. approximately rounded humeral spot in H. copelandi, H. erythrostigma, H. jackrobertsi, H. minor, H. pando, H. paepkei, H. pyrrhonotus, H. roseus, H. socolofi, and H. sweglesi; humeral spot horizontally or posteriorly elongated in H. epicharis, H. khardinae, and H. werneri; conspicuous humeral spot in H. eques, H. haraldschultzi Travassos, 1960, H. micropterus, H. megalopterus, H. simulatus and H. takasei; and absence of humeral spot in H. compresus, H. dorsalis Zarske, 2014, H. georgettae, H. pulchripinnis, and H. rosaceus].

The new species differs from H. bentosi by the absence of an extended and pointed dorsal and anal-fin tips (Figures 1, 2) [vs. extended and pointed dorsal and anal-fin tips]; and from H. hasemani by the dorsal-fin black spot shape, which is located approximately at the middle of the fin’s depth, not reaching its tip [vs. extended along all the fin, reaching its tip in adults] and by presenting tri to unicuspid teeth in the inner row of premaxillary and dentary [vs. pentacuspid teeth].

....

Geographical distribution: Hyphessobrycon piorskii sp. n. is presently known only from the upper Munim and Preguiças river basins, Maranhão State, northeastern Brazil (Figure 7).

Ecological notes: Hyphessobrycon piorskii sp.n. lives in shallow well-oxygenated streams with transparent waters flowing over different types of substrates (Figure 8). The streams where H. piorskii sp. n. specimens were collected varied from 0.90 to 10 meters wide, with a maximum depth of 1.60 meters. They possessed moderate water currents (0.1–0.7 m/s), with clear, sandy substrates with pebbles, mud, leaf litter, and submerged logs, often also presenting aquatic macrophytes. Hyphessobrycon piorskii sp. n. was found near shore among aquatic vegetation, tree roots and fallen logs. Other species found at both sites were Anablepsoides vieirai Nielsen, 2016, Apistogramma piauiensis Kullander, 1980, Astyanax sp., Cichlasoma cf. zarskei, Copella arnoldi (Regan, 1912), Crenicichla brasiliensis (Bloch, 1792), Hoplias malabaricus (Bloch, 1794), Megalechis thoracata (Valenciennes, 1840), Nannostomus beckfordi Günther, 1872, and Synbranchus marmoratus Bloch, 1795. Gut contents of C&S specimens contained algae and disarticulated arthropod remains.

Etymology: The name piorskii honors the ichthyologist Nivaldo Magalhães Piorski for his contributions to the ichthyologic knowledge of the Maranhão State.


 Erick Cristofore Guimarães, Pâmella Silva De Brito, Leonardo Manir Feitosa, Luís Fernando Carvalho-Costa and Felipe Polivanov Ottoni. 2018. A New Species of Hyphessobrycon Durbin from northeastern Brazil: Evidence from Morphological Data and DNA Barcoding (Characiformes, Characidae). ZooKeys. 765: 79-101. DOI: 10.3897/zookeys.765.23157


Resumo: Uma nova espécie de Hyphessobrycon é aqui descrita para as bacias do alto Rio Munim e Preguiças, nordeste do Brasil, sustentada por métodos morfológicos e moleculares de delimitação de espécies. Essa nova espécie é membro do grupo Hyphessobrycon sensu stricto, já que possui os três principais estados de caracteres diagnósticos desse agrupamento: presença de uma mancha marrom escura ou negra na nadadeira dorsal, ausência de uma faixa lateral no meio do flanco e a posição do aparelho de Weber localizado acima da horizontal da margem dorsal do opérculo. Nossa análise filogenética também apoia o posicionamento da nova espécie dentro desse grupo, entretanto não foi possível recuperar o grupo-irmão da espécie. Pristella maxillaris Moenkhausia hemigrammoides foram recuperados com sendo o clado irmão do grupo Hyphessobrycon sensu stricto.
Palavras-chave: clado rosy tetra, Hyphessobrycon sensu stricto, taxonomia integrativa, Pristellinae

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