Orthopristis hybrid

Marceniuk, Alexandre Pires, Caires, Rodrigo Antunes, Machado, Leonardo, Cerqueira, Najila Nolie Catarine Dantas, Serra, Rayla Roberta M. De S. & Oliveira, Claudio, 2019, Redescription of Orthopristis ruber and Orthopristis scapularis (Haemulidae: Perciformes), with a hybridization zone off the Atlantic coast of South America, Zootaxa 4576 (1), pp. 109-126 : 120-121

Orthopristis hybrid ( O. ruber x O. scapularis )

( Figure 3 , Tables 3 & 4)

Material examined. Brazil: LBP 24105, 1: 158–180 mm CP, Guarapari, Espírito Santo ; LBP 24142, 5: 96–142 mm CP, Vitória, Espirito Santos.

Morphological. Specimens with intermediate counts of rakers in the first and second gill arches, in comparison with Orthopristis ruber and O. scapularis , were identified as hybrids. These hybrids have 13–15 rakers on the lower limb of the first gill arch (vs. 10–12 in O. scapularis , Table 4g), and 17–19 rakers in the second arch (vs. 20–23 in O. ruber , Table 4h).

Molecular diagnosis. Analysis of the COI sequences indicated that all the putative hybrid specimens have sequences similar to that of Orthopristis ruber ( Fig. 2 ). In a complementary analysis, we sequenced the first intron of the nuclear S7 gene of four O. scapularis specimens from the northern coast of Brazil, five O. ruber specimens from the southern coast, and six putative hybrids. These sequences were also compared with that of O. chrysoptera (Genbank number JQ741907 ). We identified five polymorphic positions that corroborated the hybridization hypothesis ( Table 2). For example, specimens from northern Brazil have the nucleotides G or T at position 318, as in the hybrids, whereas those from southern Brazil have only G at this position ( Table 2). By contrast, the northern specimens invariably present nucleotide C at position 134, whereas the southern specimens and hybrids have either C or T at this position ( Table 2).

Distribution. Oorthopristis ruber specimens were observed off the eastern, southern and southeastern coast of Brazil, while O. scapularis were found off the northern-northeastern coast. All of the putative hybrids were found off Espírito Santo state, on the eastern Brazilian coast ( Fig. 4 ).

Color in life. Body whitish gray to silvery, head silvery, dark grey on upper head margin from snout to vertical passing through the pre-opercular margin. Small light brown spots in infraorbital region to operculum, larger (nearly ¼ pupil diameter) on the flanks over the rear border of the scales, forming faint oblique lines. Faint brown horizontal line from the rear eye border to the posterior margin of operculum, width slightly smaller than pupil length. Humeral spot and vertical bars absent. Dorsal fins hyaline with orange hue, anal fin and caudal fin dusky ( Fig. 3 ).

Color of preserved specimens. Ground color light gray, upper half of flanks with dark brown spot at center of scales forming oblique lines; head dusky on upper margin from snout to vertical passing through pre-operculum border, light gray in infraorbital region; scales on opercle with brown pigmentation ventrally, forming small irregular spots. Black spot nearly size of pupil on rear border of operculum, over opercular spine and well behind center of eye. Humeral spot conspicuous, about equal to eye size just behind opercular spot; dark bars and marking otherwise absent. Dorsal and anal fins gray with dusky hue in inter-radial membranes and distal margin; caudal fin dusky, darker in middle rays ( Fig. 3 ).

Figures

FIGURE 2. Neighbor-joining tree of the species of Orthopristis based on partial sequences of the cytochrome oxidase c subunit I. Numers near nodes represent bootstrap support.

FIGURE 3. Non type-specimens of Orthopristis hybrid (LBP), fresh (left) and fixed (right), in lateral view.

FIGURE 4. The Atlantic coast of South America, showing the geographic distribution of Orthopristis scapularis (green), Orthopristis ruber (yellow), Orthopristis hybrid (red), locations with material, in zoological collections, not examined (dark blue), and localities with record in the literature (light blue). Some symbols represent more than one locality or a large number of specimens. Non-type specimens are represented with circles, and type specimens are indicated by square