Phalloptychus iheringii (Boulenger)

Lucinda, Paulo H. F., 2005, Systematics and biogeography of the genus Phalloptychus Eigenmann, 1907 (Cyprinodontiformes: Poeciliidae: Poeciliinae), Neotropical Ichthyology 3 (3), pp. 373-382 : 377-378

Phalloptychus iheringii (Boulenger)

Fig. 5 ; Tables 1-2

Girardinus iheringii Boulenger, 1889: 266 . Type locality: Rio Grande do Sul. Restricted by Ihering (1893: 29) to “an der Mündung des Rio Camaquam” [= in the mouth of rio Camaquã].

Type material. Lectotype [present designation]: BMNH 1886.1 .21.73 . Paralectotypes: BMNH 1886.1.21.74-82 (9), CAS 62348 (33).

Diagnosis. Phalloptychus iheringii can be autapomorphically diagnosed by the possession of eight anal-fin rays in males [86-3]. Furthermore, P. iheringii can be distinguished from P. eigenmanni by the number of pelvic-fin rays in females (5 vs. 6, respectively), by the number of predorsal scales (10-12 vs. 13, respectively), and the shorther predorsal distance in females (55.6-61.3 vs. 64.0-68.6 % SL, respectively). P. iheringii is distinguished from P. januarius by the number of epipleural ribs (10-11 vs. 12-13 [one specimen had 11 in one side and 12 in the other], respectively), by the number of gonopodial rays (8 vs. 9, respectively), and by a significantly greater number of vertical bars along body sides of females (range = 8-18, median = 12 vs. range = 5-12, median = 7, respectively). Although some overlap occurs, Mann-Whitney rank sum tests ( Fig. 6 ) indicate significant differences (P <0.001).

Description. Morphometric data in Tables 1-2. Range of SL: 22.4 to 34.1 mm (females), 14.4 to 20.0 mm (males). Body compressed; width in predorsal region uniform, and about half body depth. Postdorsal region compressed towards caudal peduncle. Dorsal profile of head slightly concave. Predorsal profile convex. Dorsal-fin base oblique. Postdorsal profile concave. Pre-anal profile convex. Anal-fin base oblique; postanal profile concave. Dorsal fin with semi-elliptical border, located posterior to mid-body. Origin of dorsal fin in females at vertical passing approximately through base of second anal-fin ray; in males, origin of dorsal fin posterior to vertical passing through origin of anal fin. Pectoral fin with high insertion. Base of dorsalmost pectoral-fin ray closer to dorsal than to ventral profile. Longest pectoral-fin ray of females reaching about fifth or sixth scale in longitudinal series. In adult males, origin of pectoral fin anterior to vertical passing through origin of pelvic fin. Pelvic fin small, surpassing origin of gonopodium in male; not reaching origin of anal fin in females. Origin of anal fin of male closer to snout tip than to caudal peduncle. Mouth superior, almost aligned with base of dorsalmost pectoral-fin ray.

Dorsal-fin rays: 9 [51]. Pectoral-fin rays: 10 [7], 11 [25], 12 [6]. Pelvic-fin rays: 4 [17] (males), 5 [27] (females). Anal-fin rays (females): 10 [26]. Gonopodial rays: 8 [3]. Caudal-fin rays: 23 [13], 24 [15], 25 [12]. Predorsal scales: 10 [12], 11 [28], 12 [8]. Longitudinal series scales: 27 [16], 28 [20]. Scales around caudal peduncle: 16 [43]. Scales in transverse row: 7 [3], 8 [38]. Epipleural ribs: 10 [2], 11 [7]. Pleural ribs: 13 [1], 14 [9]. Vertebrae: 32 (12/5/15) [7], (11/5/16) [1], (11/6/15) [1]. Expanded neural processes: 4 [4], 5 [7]. Premaxillary teeth: 10 [4], 11 [1], 12 [2], 13 [1], 14 [1], 15 [1], 16 [1], 17 [1]. Dentary teeth: 8 [1], 9 [1], 10 [4], 11 [1], 13 [1], 14 [2], 16 [3], 18 [1]. Branchiostegal rays: 5 [8]. Caudal-fin rays attached to hypural plate: 9 [9]. Upper accessory cartilages: 1 [5], 2 [4]. Lower accessory cartilages: 1 [5], 2 [2].

Preorbital ramus of cephalic sensory system represented by two to five grooved neuromasts. Preorbital canal absent. Anterior portion of supraorbital ramus (pores 1 and 2a) parallel to upper lip with three inconspicuous neuromasts on each side. Posterior portion of supraorbital ramus (pores 2b, 3, 4a) composed of two grooved neuromasts. Posterior remnants of infra-orbital ramus represented by three neuromasts (pores 4b, 5, 6a) and by one short canal (pores 6b and 7). Preopercular ramus represented by large canal (sometimes completely open, forming groove) along preopercular posterolateral border and by prolonged canal along preopercle ventral border opened by four pores. Opercular canal absent. Mandibular ramus composed of two or three superficial neuromasts (pores Z, Ya, and Yb) on anterior border of ventral surface of mandible and by one superficial neuromast near maxillary distal end (pore W).

Gonopodial complex composed of three functional gonapophyses and nine gonactinosts. Gonactinosts 2, 3, 4 fused. Gonactinost 4 with wing-like expansions. Ligastyle present. Gonopodium sinistrally asymmetrical. Eight gonopodial rays. R1 and R2 unbranched and short, with 8 segments. R3 with dorsal convexity located near base ranging from second to tenth or eleventh segments 2 to 10 or 11. Tip of R3 , R4 a, and R4 p ventrally bent and joint. Dorsal convexity located between segments 12 to 20 of R 4p. Fourteen to fifteen spines on distal segments of R 4p. Spines retrorse except two or three last spines directed forwards or upwards. R6 , R7 , and R8 branched. Five or six segments before bifurcation of R6 . Anterior and posterior branches of R6 almost or fully ankylosed. Distal end of R6 modified in arrow-shaped expansion. R7 with six to eight segments anterior to bifurcation. Anterior and posterior branches of R7 moderately expanded and partially to completely ankylosed.Anterior branch of R7 greater than posterior. R8 with six or eight segments anterior to bifurcation. Anterior and posterior branches of R8 normal. Anterior branch of R8 greater than posterior. Six to eight segments on anterior branch of R8 . R9 very minute not attached to pterygiophore .

Color in alcohol. Eye greenish grey, sometimes with shining yellow iridescence. Pupil greenish brown. Ground color cream, darker in upper half. Scales surface border and subjacent skin replete with many brown chromatophores, conferring reticulate pattern to body sides. Dark brown predorsal line. Brown chromatophores scattered through whole body, more concentrated in dorsal portion, mainly on head, snout, and ventral surface of mandible. Anus margin and urogenital area light yellow. Fins hyaline. Fin rays with two rows of brown chromatophores along each side, along extension of ray. Pale brown band on dorsal fin near its base (sometimes not easily seen). Eight to 18 narrow brown bars (median = 12) along body sides of female specimens. Dark brown spot at base of R3.

Common names. Barrigudinho.

Distribution. Phalloptychus iheringii occurs in coastal drainages in Santa Catarina and Rio Grande do Sul states of Brazil ( Fig. 1 ).

Remarks. Boulenger (1889) described Girardinus iheringii in honor of Hermann von Ihering who collected and sent him the specimens on which the description has been based ( Ihering, 1893). This name has subsequently been used by Eigenmann & Eigenmann (1891) referring to Rio Grande do Sul specimens. Boulenger originally cited the type locality as “ Rio Grande do Sul ”, probably because it was the only collection information he had. Ihering (1893) states that type specimens have been collected “an der Mündung des Rio Camaquam” [= in the mouth of rio Camaquã], thus restricting the type locality. In the same paper, however, Ihering claimed that G. iheringii should be regarded as a junior synonym of G. januarius , based on information provided in letter by Hingeldorf. Presumably, for this reason, subsequent authors have considered both names synonyms. However, the study of color pattern has revealed that the number of vertical bars along body sides of females is significantly greater in southern populations of Phalloptychus from Santa Catarina and Rio Grande do Sul (range = 8-18, median = 12) than for northern populations from Rio de Janeiro, São Paulo and Paraná (range = 5-12, median = 7). See Fig. 6 for a nonparametric statistical expression of differences and simi- larities among Phalloptychus populations. These differences along with differences in number of epipleural ribs and gonopodial rays give support to the resurrection of P. iheringii as a valid species.

Examined material. Lectotype [present designation], BMNH 1886.1 .21.73, mouth of rio Camaquã , approx. 31 o 15’S 51 o 47’W. H. von Ihering . Paralectotypes, BMNH 1886.1.21.74-82 (9), same data as lectotype . CAS 62348, 20 of 33, H. von Ihering, 1893. Nontype specimens: Brazil. Santa Catarina : MCP 11016 (11), Laguna, channel connecting rio Tubarão to lagoa de Santa Marta, including pools and lateral channel, 8 Dec 1986 . MCP 11054 (107/8*), Tubarão, rio Tubarão and lateral channels near Campo Verde . MCP 11515 (1), Tubarão, rio Tubarão and lateral channels near Campo Verde, 28 Nov 1986 . MCP 26017 (11), Laguna, lagoa de Santa Marta, 27 Dec 1993 . Rio Grande do Sul: FURG 79.0554 (6), São José do Norte , 6 Sep 1979 . FURG 79.0652 (8), Rio Grande, Ponta da Marambaia , 16 Mar 1979 . FURG 80.0238 (6), Rio Grande, Ilha dos Marinheiros, Porto Rei , 2 Apr 1980 . FURG 80.0326 (6), Rio Grande , 11 Nov 1980 . FURG 80.0327 (5), Rio Grande, Ilha do Leonildo , 24 Mar 1980 . FURG 82.0339 (1), Rio Grande , 19 Jan 1982 . FURG 82.0340 (2), São José do Norte , 18 Jan 1982 . FURG 82.0341 (1), Rio Grande , 1 Mar 1982 . MCP 25670 (2), Mostardas, swamp in road Talhamar to Parque Nacional da Lagoa do Peixe , 4 Feb 2000 . MCP 26060 (2/1*), Rio Grande, Ilha dos Marinheiros , Porto Rei, 2 Apr 1980 . MCP 26061 (3/1*), Rio Grande , 11 Nov 1980 . MCP 26062 (2/1*), Rio Grande, Ilha dos Marinheiros, Ponta da Marambaia , 16 Mar 1979 . UMMZ 65274 (2), 1893 . USNM 235355 (5), Rio Grande, Ilha dos Marinheiros, Porto Rei , 22 Dec 1980 . USNM 55640 (3), Rio Grande do Sul .

Figures

Fig. 5. Phalloptychus iheringii, MCP 11054, Tubarão, rio Tubarão and lateral channels near Campo Verde, Santa Catarina,Brazil.(a) male, 18.3 mmSL; (b)female, 25.7 mmSL.

Fig. 6. Tukey box plot of number of bars along flanks in female specimens of Phalloptychus januarius and P. iheringii. Significant differences were found between P. januarius (Rio de Janeiro, São Paulo and Paraná) and P. iheringii populations (Santa Catarina and Rio Grande do Sul). * Type locality of P. januarius, ** type locality of P. iheringii.

Fig. 1. Coastal drainages from Bahia to Rio Grande do Sul, and Uruguay showing distribution of Phalloptychus eigenmanni (triangle), P. januarius (squares), and P. iheringii (circles). Each symbol may represent more than one lot and/ or locality. T = type locality.