Neoconger mucronatus Girard, 1858

Smith, David G., Marceniuk, Alexandre P., Rotundo, Matheus M., Carvalho, Cintia O. & Caires, Rodrigo A., 2024, A review of the genus Neoconger (Anguilliformes: Moringuidae), with the description of a new species, Zootaxa 5492 (1), pp. 109-128 : 113-116

Neoconger mucronatus Girard, 1858

( Figures 2 , 4 , 9 ; Tables 2 , 3 )

Neoconger mucronatus Girard, 1858: 171 ; St. Josephs Island, Texas, lectotype USNM 861. Smith & Castle 1972: 200 (redescription, synonymy, lectotype designation, osteology, life history). Smith 1989a: 60 (updated account with additional material and analysis).

Study material (18 specimens, 98–302 mm TL). LECTOTYPE: USNM 861 (female, 302), St. Joseph Island , Texas . PARALECTOTYPES: MCZ 36006 (1, 267), same data as lectotype. USNM 204928 (3 females, 263–267), same data as lectotype . OTHER MATERIAL: ANSP 94213 (1 female, 256), 28° 01.5’N, 96° 48.5’W, 7 fm (12.8 m) , 15 Aug 1960, Oregon 2916. ANSP 110071 (1, 265 +), 27° 45’N, 96° 10’W, 40–45 fm (73.2–82.3 m), 2 Feb 1958, Silver Bay 276. ANSP 136001 (1, 176), Texas. FSBC 9078 (1 male, 159), off Port Mansfield , Texas, 35 fm (64.0 m), 7 Sep 1975. TCWC 3981.1 (1 male, 107), 25° 20.0’N, 97° 02.0’W, 40–45 m, 10-ft otter trawl, 18 Nov 1975. TCWC 6097.1 (6 females, 187–265), 18° 50.0’ N, 93° 43.0’ W, 158–170 m, 10-ft otter trawl, 12 Nov 1975. USNM 154997 (1 female [?], 98), 27° 03’ 30” N, 97° 04’ 38” W, 18 fm (32.9 m), 17 Feb 1939, Pelican 121-4. USNM 154998 (1 female, 209), 27° 46’ N, 96° 55’ 30” W, 11 fm (20.1 m), 20 Apr 1938, Pelican 38-2. Uncatalogued (1, cleared and stained), no data .

Diagnosis. Neoconger mucronatus differs most distinctly from the geographically adjacent Neoconger torrei in the total number of vertebrae, 94–99 vs 104–107 respectively. It differs from N. anaelisae in the number of predorsal vertebrae (38–44 vs 32–34). It differs from N. hygomi in the number of predorsal vertebrae (38–44 vs 48), preanal vertebrae (43–47 vs 55), precaudal vertebrae (ca. 50–52 vs 58), and total vertebrae (94–99 vs 107). It differs from N. vermiformis in the number of predorsal vertebrae (38–44 vs 34–38), preanal vertebrae (43–47 vs 41–44), and precaudal vertebrae (ca. 50–52 vs 45–ca 49). Larvae have a sharp intestinal loop; the posterior lateral melanophore is present, the anterior ventral melanophore is absent.

Description. See genus account for general appearance. Morphometric characters in % TL: preanal length 48.4–53.5, predorsal length 45.3–54.2, head length 8.9–11.1, depth at anus 2.9–4.8. In % HL: snout 17.8–21.9, eye 7.8–8.2 in males and 3.1–7.1 in females, snout-rictus 27.6–31.9, gill opening 9.5–18.5, interbranchial 9.4– 11.2 in males and 11.8–18.5 in females, pectoral-fin length 32.7–34.5 in males and 17.0– 24.5 in females. Meristic characters: lateral-line pores 22–40, mandibular pores 6, pectoral-fin rays 9–12, predorsal vertebrae 38–44, preanal vertebrae 43–47, total vertebrae 94–99, precaudal vertebrae ca. 50–52.

Mandibular pores arranged as follows ( Fig. 4 ). First pore at level of anterior nostril. Second pore slightly posterior to level of anterior nostril. Third pore slightly anterior to level of posterior nostril. Fourth pore between level of anterior nostril and anterior margin of eye. Fifth pore directly below eye. Sixth pore behind level of eye, approximately below level of rictus.

Color in preservative gray to brown, sometimes with darker reticulations. Freshly caught specimens may show some red color on vertical fins, head, and pectoral fins, apparently caused by blood in superficial vessels and tissue. Pores on lower jaw sometimes surrounded by whitish area. Stomach and intestine pale.

Maximum size appears to be about 300 mm TL. The largest specimen examined was the lectotype, 302 mm TL.

The two confirmed males differ in several characters from the 12 females: lesser preanal length (48.4–50.5 vs 51.3–53.5 %TL), lesser predorsal length (45.3–45.8 vs 49.4–54.2 %TL), greater eye diameter (7.8–8.2 vs 3.1–7.1 %HL), longer pectoral fin (32.7–34.5 vs 16.0–24.5 %HL), fewer predorsal vertebrae (38 vs 41–44), and fewer preanal vertebrae (43 vs 46–47).

Distribution. Found in the western Gulf of Mexico between the mouth of the Mississippi River and the Yucatan Peninsula at depths of 12– 170 m., where it seems to be reasonably common. This area is characterized by predominantly muddy bottoms.

Etymology. Latin mucro (sharp, pointed); natus (born). Apparently referring to the relatively pointed anterior end of the head.

Figures

FIGURE 2. Neoconger mucronatus, paralectotype, MCZ 36006.

FIGURE 4. Head pores in Neoconger mucronatus, modified from Smith 1989a: fig 50.

FIGURE 9. Leptocephalus of Neoconger mucronatus, from Smith 1989b: fig. 721.

Tables

TABLE 2. Numbers of vertebrae in species of Neoconger

Species	Predorsal	Preanal	Total
N. mucronatus	38–44	43–47	94–99
N. torrei	42–45	48–49	104–107
N. anaelisae	32–34	42–44	98–104
N. hygomi	48	55	107
N. vermiformis	34–38	41–44	93–102