Mystriophis, Kaup, 1856

Luz, Alciany Nascimento Da, Correia, Sandra Margarida, Lopes, Evandro P., Jimenez, Jose Gonzalez, Traore, Diafodé & Psomadakis, Peter Nick, 2025, A new species of the genus Mystriophis (Anguilliformes: Ophichthidae) from Cabo Verde (Eastern Central Atlantic), with notes on two Mystriophis specimens documented on the R / V Dr. Fridtjof Nansen, Zootaxa 5632 (2), pp. 293-308 : 307

Key to the species of Mystriophis

Note: due to limited information on its morphological characteristics, Mystriophis sp. A (from off Angola, sensu McCosker 2016) is not included in the below key.

1a Dorsal-fin origin in front of pectoral-fin tip; inner and outer row maxillary teeth subequal in size; 12 pectoral-fin rays; 64/63 lateral line pores anterior to anus; predorsal length 117.4 % HL; distance between upper end of gill opening and origin of dorsal fin 18.4 % HL; colour when fresh dark brown with white markings on sides of head and jaws..... M. caboverdensis sp. nov.

1b Dorsal-fin origin above or behind pectoral-fin tip; outer row maxillary teeth larger than inner row teeth; 13–14 pectoral-fin rays; 55–58 lateral-line pores anterior to anus; predorsal length 123.9–147.8 % HL; distance between upper end of gill opening and origin of dorsal fin 23.9–47.8 % HL; ochre to light reddish brown with no white markings on sides of head and jaws...... 2

2a Teeth in jaws and palate ungrooved; interorbital width 8.7–11.8 % HL; interbranchial distance 8.7–11.9 % HL; preanal length 45.5–48.7 % TL; predorsal length 134.1–147.8 % HL; total vertebrae 136–144; wavy longitudinal lines of darker tone forming the deep part of dermal folds on head and anterior part of body; deep-water species occurring at 75–400 m depth M. crosnieri

2b Teeth in jaws and palate grooved at tips; interorbital width 4.2–8.5 % HL; interbranchial distance 5.2–8.3 % HL; preanal length 40.4–44.3 % TL; predorsal length 123.9–135.3 % HL; total vertebrae 154–158; wavy longitudinal lines of lighter tone forming the deep part of dermal folds on head and anterior part of body; coastal (including lagoons) species not exceeding 40 m depth......................................................................................... M. rostellatus