Lycengraulis figueiredoi, Loeb, Marina Vianna & Alcântara, Ayda Vera, 2013

Loeb, Marina Vianna & Alcântara, Ayda Vera, 2013, A new species of Lycengraulis Günther, 1868 (Clupeiformes: Engraulinae) from the Amazon basin, Brazil, with comments on Lycengraulis batesii (Günther, 1868), Zootaxa 3693 (2), pp. 200-206 : 201-204

Lycengraulis figueiredoi , sp. n.

( Fig. 1 , Tab. 1 )

Lycengraulis amazonensis Alcântara, 1972:19 [not a valid name, described as new in Alcântara's unpublished master thesis].— Whitehead et al., 1985:391 [erroneously considered a junior synonym of Lycengraulis grossidens ].

Holotype. MZUSP 6032, 129.80 mm SL. Brazil, Amazonas, lago Beruri, rio Purus, 3°50'S 61°20'W, 7–8 April 1967, Expedição Permanente da Amazônia.

Paratypes. All from Brazil. ANSP 193934 (2, 64.9–78.8 mm SL), INPA 39522 (2, 63.6–77.0 mm SL), MNRJ 40719 (2, 66.32–81.86 mm SL): Pará, rio Trombetas, Oriximiná, 1°46'S 55°52'W, 12–15 October 1967, Expedição Permanente da Amazônia. MZUSP 6363 (1, 101.2 mm SL), Amazonas, lago Castro, rio Purus at mouth, 7–8 April 1967, Expedição Permanente da Amazônia. MZUSP 9815-21 (5, 112.11– 123.24 mm SL), Amazonas, lago Beruri, rio Purus, 7–8 April 1967, Expedição Permanente da Amazônia. MZUSP 6749 (1, 118.6 mm SL), Amazonas, rio Negro at Manaus neighborhood, 15–23 November 1967, Expedição Permanente da Amazônia. MZUSP 7658 (1, 152.4 mm SL), Amazonas, lago José Açu at mouth, Parintins, 11–12 December 1967, Expedição Permanente da Amazônia. MZUSP 9822 (15, 52.2–78.6 mm SL), Pará, rio Trombetas, Oriximiná, 1°46'S 55°52'W, 12–15 October 1967, Expedição Permanente da Amazônia. MZUSP 5537 (1, 169.6 mm SL), Pará, Lago Jacupá, Oriximiná, February 1967, Expedição Permanente da Amazônia.

Diagnosis. Lycengraulis figueiredoi can be distinguished from L. grossidens by a short upper maxilla, its posterior margin not reaching the lower maxilla joint (vs. upper maxilla longer, its posterior margin reaching to or a little past of mandible joint). Lycengraulis figueiredoi can be distinguished also from L. poeyi by 26 to 31 anal-fin rays (vs. 21 to 23 anal-fin rays) and by 44 to 46 vertebrae (vs. 42 vertebrae), and from L. batesii by having the analfin origin at vertical through base of second to fifth dorsal-fin ray (vs. anal-fin origin at vertical through base of sixth to 10th dorsal-fin ray) and by 17–21 gill rakers on the lower branch of first gill arch (vs. 12–15 gill rakers on the lower branch of first gill arch).

Description. Morphometric data of the holotype and 30 paratypes are presented in Table 1 . Body elongate, laterally compressed; greatest body depth at vertical through dorsal-fin origin. Dorsal body profile gently convex from tip of snout to vertical through posterior margin of posterior nostril, convex from latter point to the top of the head, approximately straight from the top of the head to dorsal-fin origin, straight and downward along dorsal-fin base, approximately straight along caudal peduncle. Ventral body profile gently convex from anterior tip of lower jaw to posterior margin of orbit, convex from latter point to the posterior end of anal-fin base, nearly straight along caudal peduncle. Caudal peduncle longer than deep. Vertebrae 44–46 (n = 8).

Conical-shaped head. Snout short, conical in lateral view. Mouth sub-terminal, inclined downward relative to body axis. Upper maxilla short and thin, posterior margin rounded, extending beyond the vertical through posterior margin of orbit, not reaching the mandible joint. Premaxilla, maxilla and dentary bearing one row of teeth. Teeth enlarged, well-spaced canine-like and slightly recurved at premaxilla and maxilla. Dentary with larger teeth intercalated with smaller ones.

Eye lateral on head, located dorsal to horizontal through pectoral-fin insertion; eye visible in dorsal and ventral views. Two confluent nostrils on each side of the head, the anterior elliptical and the posterior crescent-sharped. Perforated scale on the lateral line absent. Cicloid scales higher than large, deciduous.

Dorsal-fin rays ii–iii+11–13 (n = 31), its origin closer to caudal-fin base than to tip of snout; dorsal-fin distal margin approximately straight in juveniles, slightly convex in adults. Anal-fin rays ii–iii+24–28 (n = 26), its origin at vertical through base of second to fifth dorsal-fin rays, anterior rays longer. Pectoral-fin rays i+13–14 (n = 31); distal tip of longest pectoral-fin ray reaching pelvic-fin origin; pectoral-fin distal margin slightly convex. Pectoralfin axillary scale longer than half of pectoral-fin length, absent in most specimens, probably lost during collecting or storage. Pelvic fin-rays i+6 (n = 31), its pelvic-fin origin in midpoint of distance from pectoral-fin origin to anus; distal tip of longest pelvic-fin ray not reaching anal-fin origin; pelvic-fin distal margin slightly convex. Pelvic-fin axillary scale smaller than pectoral fin, absent in most specimens, probably lost during collecting or storage. Pelvic-fin origin closer to the base of the anteriormost pectoral-fin ray than to anal-fin origin. Caudal-fin rays 8,10,9,7, forked, lobes similar in size. Dorsal and ventral procurrent caudal-fin rays 8,7 respectively (n = 3 C&S).

Pseudobranch present, shorter than eye. Gill rakers on the first branchial arch long and thin in juveniles, short and thick in adults, 13–16 (n = 31) on the upper branch, 17–21 (n = 31) on the lower branch, 31–36 (n = 31) in total. Length of raker inserted in the angle of first gill arch smaller than orbital diameter.

Coloration in alcohol. Body coloration pale to light yellow, juveniles with lighter coloration. Longitudinal stripe brownish to silver, absent in most preserved specimens, when present extending from the posterior margin of head to caudal peduncle; width of the stripe of about 20% of body depth at vertical through pectoral-fin origin. Caudal-fin borders and gill cavity darkened. Dark spots dorsally on the head, along dorsal portion of body, along dorsal margin of longitudinal line and along base of dorsal and caudal fins. Orbit and middle portion of the postorbital region translucent to pale.

Etymology. The specific name was given in honor of José Lima de Figueiredo, a Brazilian ichthyologist from the Museu de Zoologia da Universidade de São Paulo who contributed significantly to the study of fish systematics in Brazil.

Distribution. Lycengraulis figueiredoi is known only from lago Castro and lago Beruri, in the drainage of rio Purus; rio Negro; lago José Açu at Parintins; lago Jacupá and rio Trombetas at Oriximiná, middle Amazon basin, Amazonas and Pará State, Brazil.

Figures

FIGURES 1. Lycengraulis figueiredoi, holotype, MZUSP 6032, 67.6 mm SL, Amazonas, lago Beruri at rio Purus, Brazil.

Tables

TABLE 1. Morphometrics and meristics of Lycengraulis figueiredoi, new species. SD = Standard Deviation, frequency in parenthesis.

Morphometrics	Holotype	n Range Mean	SD
Standard length (mm) Head length (mm) Percentages of standard length	129.8 30.2	30 52.2 169.6 85.6 30 12.5 41.1 20.9	29.5 6.8
Body depth	20.6	30 19.1 24.4 21.7	1.3
Caudal peduncle depth	8.8	30 8.2 11.2 9.9	0.6
Dorsal-fin base length	11.2	30 10.0 13.9 12.0	0.8
Anal-fin base length	22.8	30 25.6 31.0 27.3	1.1
Pectoral fin length	19.7	30 13.4 21.6 18.2	2.3
Pelvic fin length	10.5	30 9.0 13.5 10.7	1.2
Prepelvic length	40.9	30 38.0 45.2 42.4	1.7
Prepectoral length	24.3	30 21.7 26.5 24.7	1.2
Predorsal length	55.3	30 55.2 86.2 59.0	5.3
Preanal length	56.8	30 57.5 62.6 60.5	1.5
Head length	23.3	30 22.5 26.8 24.6	0.9
Percentages of head length
Cheek length	47.7	30 35.3 48.8 39.8	3.7
Snout length	14.6	30 11.0 15.5 12.7	1.2
Orbital diameter	27.8	30 19.2 27.9 24.6	2.5
Upper jaw length	74.8	30 67.7 78.2 71.3	2.8
Postorbital distance	63.0	30 57.1 66.8 62.7	2.6
Gill raker angle on1st gill arch length Meristics	11.9 Holotype	30 9.0 15.7 11.9 n Range	2.0
Dorsal-fin rays	ii+11	30 13(2),14(16),15(11),16(1)
Anal-fin rays	iii+23	25 26(1),27(1),28(7),29(6),30(8),31(2)
Pectoral-fin rays	i+14	30 14(22),15(8)
Pelvic-fin rays	i+6	30 7(30)
Vertebrae	-	8 44(1),45(6),46(1)
Gill rackers on1st gill arch Upper branch	14	30 13(2),14(21),15(7),16(1)
Lower branch	20	30 17(4),18(9),19(13),20(4),21(1)
Total	34	30 31(5),32(4),33(14),34(6),35(1),36(1)