Aulopus chirichignoae, Béarez & Zavalaga & Miranda & Mennesson & Campos-León & Jiménez-Prado, 2024

Béarez, Philippe, Zavalaga, Fabiola, Miranda, Junior, Mennesson, Marion I., Campos-León, Sarita & Jiménez-Prado, Pedro, 2024, Aulopus chirichignoae, a new flagfin from the eastern Pacific Ocean (Teleostei, Aulopiformes, Aulopidae), Zootaxa 5458 (1), pp. 108-118 : 110-116

Aulopus chirichignoae , sp. nov. Béarez, Zavalaga & Miranda

English vernacular name: Pacific royal flagfin

Spanish vernacular name: Lagarto real del Pacífico

French vernacular name: Limbert royal du Pacifique

( Fig. 2 , Tables 2–3 )

Aulopus bajacali (non Parin & Kotlyar)— Ambrose (1996) in part, description; Thompson (1998) in part, description, Fig. 1 A–C , and distribution; Nakaya et al. (2009: 133), description, Fig. 88.

Aulopus sp. —Chrichigno et al. (2001: 21).

Aulopus n. sp. —Jiménez-Prado and Béarez (2004: 25).

Holotype. IMARPE-19082, mature male, 301 mm SL, Pacific Ocean , Cabo Blanco, Peru (4°13’46.50”S, 81°14’37.39”W), 91.4 m, jigging, coll. J. Miranda, 22 May 2022 ( Fig. 2A ).

Paratypes. MNHN-IC-1997-3820, mature female, 236 mm SL, Puerto López , Ecuador (1°33’S, 80°49’W), bottom longlining, coll. P. Béarez, 13 Dec. 1996 ; MNHN-IC-1999-0963 mature male, 335 mm SL, Puerto López , Ecuador, bottom longlining, coll. J. Vera, 15 Nov. 1998 ; IMARPE-19086, mature female, 325 mm SL ( Fig. 2B ) and IMARPE-19087, mature male, 308 mm SL, Cabo Blanco , Peru (4°15’S, 81°14’W), 73 m, jigging, coll. J. Miranda, 29 May 2022 ; MEPN-I 19659 , mature male, 300 mm SL and MECN-DP 5536 , female, 188 mm SL, Puerto López, Ecuador, bottom longlining, coll. P. Béarez, 24 June 2000 .

Other specimens examined but not designated as paratypes: MNHN-IC-2001-1364 (three specimens, males and females, ranging from 176 to 280 mm SL) collected with paratypes from Ecuador ; IMARPE-19083 (female, 262 mm SL) collected with the holotype; IMARPE-19084 (male, 252 mm SL), IMARPE-19085 (male, 290 mm SL), IMARPE-19088 (male, 307 mm SL), IMARPE-19089 (male, 317 mm SL), IMARPE-19090 (male, 313 mm SL), collected with paratypes from Peru .

Diagnosis. A species of Aulopus as defined by Thompson (1998), characterized by the following combination of characters: adult males possessing elongate filaments on dorsal rays 2–4 with females lacking these filaments; small (29.4–31.4% SL) head length; narrow (4.8–5.5% SL) bony interorbital width; dorsal and anal fin rays counts modally 15 and 11, respectively, and 50–51 vertebrae ( Tables 2 and 3). A large species for the genus, largest specimen examined 335 mm SL.

Molecular analysis. Among the five paratypes used for DNA barcoding, only two sequences of the COI gene (623 bp) from IMARPE-19086 and 19087 were obtained. The two sequences were deposited in the BOLD under process numbers ACHIR001-24 and ACHIR002-24. The maximum likelihood tree supported the recognition of a new species of Aulopus near the coasts of Peru and Ecuador ( Fig. 3 ), which differs from Aulopus filamentosus ( Italy, Portugal, Cape Verde and Bermuda) and A. bajacali ( Mexico) with a 4.2% and 2.8% divergence, respectively. A sequence of an Aulopus sp. collected in the TEP (MPD-2008, Paramount) matches the new species with a 0.4% divergence ( Table 4 ).

Description —Head length 30.2% (29.4–31.4%) of SL; body width at pectoral fin 13.6% (12.0–16.3%) of SL; big and rounded eyes, horizontal diameter about 6.6% (6.6–8%) of SL; bony interorbital width about 5.5% (4.8– 5.5%) of SL. Large, slightly oblique mouth, extending almost to the rear edge of the eye. Dorsal fin rays 15 (14–15, modally 15); anal fin rays 10 (10–12, modally 11); caudal fin rays 20 (18–20, modally 10+9); pectoral fin rays 12 (12–14, modally 13); pelvic fin rays 9, the fourth being the longest. Lateral line scales 52 (49–52). Predorsal scales 18 (14–18). Total gill rakers on first arch 11 (10–12, modally 11): 2–3 on upper limb, 1 at the junction, 7–8 on lower limb. Branchiostegal rays 15 (12–15, modally 15). Body covered with strong ctenoid scales. Total vertebral number 51 (50–51: 30 + 20–21). See Tables 2 and 3 for additional meristic and morphometric values.

Sagitta (saccular otolith) oblong with regularly rounded ventral margin ( Fig. 4 ); rostrum long, pointed, dorsally flexed; dorsal margin irregular, antirostrum poorly developed; sulcus almost straight, slightly curved posteriorly, ending close to the postero-ventral corner; posterior region irregular, more prolonged dorsally than ventrally.

Fresh colors: Body dark brown dorsally, with darker greenish patches, gray ventrally. Dorsal fin whitish with irregular-shape orange and yellow spots. Pelvic fin yellowish with yellow and orange markings distally. Translucent pectoral fin with no markings. Whitish anal fin with two more or less visible longitudinal yellow stripes, one at the base of the fin and the other more or less in the middle. Adipose fin with orange spot. Caudal fin brownish at base, becoming paler distally, with alternating transverse orange mottling. Color pattern scarcely varies between males and females, but males seem to have more pronounced yellow and orange markings on their fins.

Size. The largest specimen of A. chirichignoae is a mature male 400 mm TL, 335 mm SL (MNHN-IC-1999- 0963, paratype from Ecuador). It is larger than the largest known A. bajacali sensu Thompson (1998) , a 191 mm SL female (NB—Several large A. bajacali listed in Thompson (1998) are probably A. chirichignoae ).

Distribution. Aulopus chirichignoae sp. nov. is known from the southeastern tropical Pacific Ocean along mainland Ecuador and northern Peru coasts, at depths between 70 and 150 m. However, the specimen MPD-2008 caught in 2002 on the Paramount Seamount (3°20.35’N, 90°47.88’W) genetically corresponding to Aulopus chirichognae sp. nov., indicates that the species probably has a much larger distribution.

Etymology. This species is named for Norma Chirichigno Fonseca in recognition of her research on Peruvian marine fishes and for her first mention of an Aulopus species in Peru ( Chirichigno, 1976; Chirichigno & Cornejo, 2001).

Figures

FIGURE 1. Map of the area with collection localities of Aulopus chirichignoae sp. nov.

FIGURE 2. Aulopus chirichignoae sp. nov. A. IMARPE-19082, fresh holotype, male, 301 mm SL, Cabo Blanco, Peru; B. IMARPE-19086, fresh paratype, female, 325 mm SL, Cabo Blanco, Peru (Photos by J. Miranda).

FIGURE 3. Maximum likelihood tree of the cytochrome c oxidase subunit 1 (COI) of aulopid and paraulopid species. Aulopus clade in bold. Numbers at each node represent bootstraps.

FIGURE 4. Inner view of left (A) and right (B) sagittae of Aulopus chirichignoae sp. nov. (IMARPE-019088)

Tables

TABLE 2. Frequency distributions of fin rays, lateral-line scales, and vertebrae counts for Aulopus bajacali* and Aulopus chirichignoae sp. nov.

	Dorsal rays											Number of specimens
			14						15
Aulopus bajacali			27						2			29
Aulopus chirichignoae			4						12			16
	Anal rays
	10				11		12				13
Aulopus bajacali	-				2		21				7	30
Aulopus chirichignoae	2				10		4				-	16
	Pectoral rays
	12				13					14
Aulopus bajacali		-			27					3		30
Aulopus chirichignoae	3				12					1		16
	Lateral-line scales
	48		49		50		51				52
Aulopus bajacali	5		17		6			1			-	29
Aulopus chirichignoae	-			7	1			6			2	16
	Vertebrae
	47		48		49	50		51			52
Aulopus bajacali	1		24		4	-			-		-	29
Aulopus chirichignoae	-		-		-	1		12			3	16

*The data for Aulopus bajacali considered herein were taken from Thompson (1998), though only the information referring to specimens from Baja California was used.