Neoconger anaelisae ( Tommasi, 1960 )

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 : 118-119

Neoconger anaelisae ( Tommasi, 1960)

( Figures 5 , 6 , 11 ; Tables 1–5 )

Leptocephalus anaelisae Tommasi, 1960: 93 , fig. 3; off the Amazon region of Brazil, 02° 27.5’ N, 44° 02.5’ W, holotype lost. Smith 1989b: 701 (synonym of Neoconger mucronatus ). Melo & Caires 2016: 2 (leptocephali described by Tommasi; synonym of Neoconger mucronatus ).

Neoconger mucronatus, Smith, 1989a: 60 (in part).

Neoconger sp. , Marceniuk et al., 2019: 7, 13, table 1, fig. 4b (listed; photograph). Caires et al. 2021: 127 (short description; photograph).

Study material (3 specimens, 132–254 mm TL). HOLOTYPE (by monotypy, no catalog number given): lost. NEOTYPE (designated here): MPEG 38951 (1, 254 mm TL), Brazil, Amapá Prov., 03° 44’ 05” N, 50° 18’ 48” W, 58.5 m, 16 Mar 2018 . OTHER MATERIAL: AZUSC 5785 (1, 135), Brazil, Pará Prov., 0° 05’ 56” N, 48° 31’ 10” W, 10 m, 09 Aug 2018. USNM, 214062 (1, 156), Brazil, Pará Prov., 1.87° N, 48.35° W, 42–44 m, Geomar sta. 156 .

Diagnosis. Neoconger anaelisae has fewer predorsal vertebrae (32–34) than any of the other Atlantic species (38–48) and overlaps only slightly with N. vermiformis (34–38). It further differs from N. mucronatus in total vertebrae (98–104 vs 94–99); from N. torrei in preanal vertebrae (42–44 vs 48–49) and total vertebrae (98–104 vs 104–107); from N. hygomi in preanal vertebrae (42–44 vs 55) and total vertebrae (98–104 vs 107); and slightly from N. vermiformis in total vertebrae (98–104 vs 93–102). The larva has a flatter intestinal loop than the other species; the posterior lateral melanophore is present, but the anterior ventral melanophore is apparently absent (see Notes on Leptocephali below).

Description. See genus account for general appearance. Morphometric characters in % TL: preanal 48.7–53.8, predorsal 37.2–39.7, head 10.7–11.1, depth at anus 3.0–3.5. In % HL: snout 19.2–21.7, eye 3.1–4.8, interorbital 13.2–13.7, snout-rictus 34.9–40.8, gill opening 7.5–12.8, interbranchial 12.8–23.5, pectoral fin 14.5–20.2. Meristic characters: lateral-line pores 32–35, predorsal vertebrae 32–34, preanal vertebrae 42–44, precaudal vertebrae 49– 56, total vertebrae 98–104. Mandibular pores as in N. mucronatus .

Color of freshly caught specimen gray to reddish brown.

The largest specimen is 254 mm TL.

Distribution. The three adult specimens were collected on the continental shelf off the coast of northern Brazil near the mouth of the Amazon River. The holotype of Leptocephalus anaelisae was collected in the same general area but farther offshore (2 ° 27.5’ N, 44° 02.5’ W). Smith (1989a: 64) reported that the larvae of this species extend northward to the Guianas and the eastern Caribbean, where they co-occur with larvae of Neoconger torrei . If this pattern occurs in adults as well, it would be added evidence for the distinction of these two species.

Remarks. The description of Leptocephalus anaelisae is somewhat problematic. The single type specimen is lost, and the reported number of total myomeres (93) is well below the vertebral counts of the adults (98–104). In addition, the specimen is stated to lack a pectoral fin, which is present in all larval Neoconger . Nevertheless, the illustration clearly shows a Neoconger larva, and the type locality is close to the area where the three adult specimens were collected. We therefore designate one of the adult specimens, MPEG 38951, as the neotype and hence fix the name to that specimen. Supporting the morphological diagnosis, the DNA barcoding sequences from Neoconger anaelisae show that the analyzed specimen has a K2P genetic distance between 4.0% and 23 distinct haplotypes ( Table 4 and Table 5 ) from N. torrei (see above), corroborating its recognition as a distinct species.

Etymology. Named by Tommasi for his daughter, Ana Elisa.

Figures

FIGURE 5. Neoconger anaelisae, lectotype, MPEG 38951, freshly caught.

FIGURE 6. Neoconger anaelisae, lectotype, MPEG 38951, preserved.

FIGURE 11. Leptocephalus of Neoconger anaelisae, from Tommasi 1960: fig. 3.