Neobythites kenyaensis Nielsen, 1995

Uiblein, Franz & Nielsen, Jørgen G., 2019, Redescription of the ocellus-bearing cuskeel Neobythites kenyaensis (Ophidiidae), with new Southeast African records and remarks on intraspecific morphological and colour variation, Cybium 43 (1), pp. 109-116 : 111-112

Neobythites kenyaensis Nielsen, 1995

( Figs 1-6 ; Tabs I, II)

Neobythites kenyaensis Nielsen, 1995: 5

Neobythites kenyaensis : Nielsen, 2002: 37

Holotype. – SAIAB (earlier RUSI) 13952, 124 mm SL, off Ras Ngomeni , Kenya, 2°50’S- 40°31’E, R / V Dr. Fridtjof Nansen, 275 m depth.

Paratype. – BMNH 1939.5 .24.1439, female, 103+ mm SL, off Zanzibar, Tanzania, 5°34’24”S- 39°14’05”E ; R / V John Murray, 238-293 m depth .

Other material (n = 13; 12 specimens and one unvouchered photograph; 97-162+ mm SL). – Kenya: USNM 340896, 140 mm SL; off Ras Ngomeni, 2°56’S- 40°28’E, R / V Anton Bruun , 240 m depth ; Tanzania: ZMA 113428, 148 mm SL, off Dar es Salaam, 274-457 m depth ; Mozambique: SAIAB 82154 , 3 , 135-151 mm SL, 21°15’46”S- 35°39’41”E, R / V Dr. Fridtjof Nansen (Station BT 70), 394-400 m depth ; SAIAB 98890 , two females, 97-102 mm SL, R / V Dr. Fridtjof Nansen (Station BT 135), 12°41’43”S- 40°40’E, 292-296 m depth ; SAIAB 98891 , 3 females, 101-121 mm SL, 11°08’28”S- 40°46’11”E, R / V Dr. Fridtjof Nansen (Station BT 136), 391-412 m depth ; SAM F033865 , female, 143 mm SL, 25°32’S- 34°19’E, R / V Algoa , 372 m depth ; South Africa: SAIAB 188287 , 162 + mm SL, off Tugela Bank, 29°07.5’S- 31°45.00’E, F/ V O�ean Spray , 300-350 m depth ; unvouchered photograph ( Fig. 2D ): SAIAB 95778, 148 mm SL, South Africa, Natal, off Durban, 29°54’54”S- 31°19’46”E, F/ V O�ean Spray , 427-435 m depth (photographer: Desmond Hayes).

Diagnosis

No spines on hind margin of preopercle; dorsal fin-rays 97-102; anal-fin rays 80-84; pectoral fin-rays 26-32; precaudal vertebrae 13; total vertebrae 55-59; pseudobranchial filaments 2-4; long gill rakers on anterior arch 8-10; head length 19.5-21.5% SL; pelvic-fin length 9.9-12.0% SL, pelvic fins reaching about halfway to anus; orbit length 4.3-5.3% SL, 22.0-30.5% head length, and 1.8-2.1 times in upper-jaw length; longest gill filament 1.4-2.3% SL and 6.9-12.0% head length; dorsal fin with two ocelli, the first one anterior of anus (“anterior ocellus”) and the other ocellus centrally on body well behind anus (“central ocellus”); anterior ocellus spot distance 29.5-34.5% SL, the spot covering 6-9 dorsal-fin rays; central ocellus-spot distance 53-57% SL, the spot covering 8-15 dorsal-fin rays; caudal fin entirely and dorsal and anal fins at least in their posterior parts dark pigment- ed; otolith length 4.9-5.8% SL, sulcus length 3.4-4.7% SL, ostium height 20.0-24.0% sulcus length, and ostium height 28.5-37.5% ostium length.

Description (based on the two types, 12 additional specimens, and one unvouchered photograph)

Rather elongate fish with complete but mostly indistinct lateral line; head and body covered with cycloid scales; origin of dorsal fin above proximal part of pectoral fin; origin of anal fin in front of midpoint of fish; tip of pectoral fins ending well in front of anal fin; pelvic fins reaching almost halfway to origin of anal fin; length of blunt snout about diam- eter of eye; upper jaw ending well posterior to eye; anterior nostril ending in a short tube and larger posterior nostril with a low ridge; no spines on preopercle; strong opercular spine; anterior gill arch with 2-3 blunt and two long rakers on upper branch; one long raker in angle and lower branch with 5-7 long (total long gill rakers 8-10) and 5-7 blunt rakers; gill filaments 1.1-1.4 times as long as longest gill rakers; distinct pseudobranchial filaments 2-4 (2-3).

Figures

Figure 1. – Map with sampling localities for Neobythites kenyaensis. Number of specimens indicated for localities with multiple occurrences.

Figure 2. – Photographs of fresh specimens of Neobythites kenyaensis. A: SAIAB 98891, 121 mm SL, northern Mozambique (F. Uiblein); B: SAIAB 98891, 101 mm SL, northern Mozambique (F. Uiblein); C: SAIAB 82154, 136 mm SL, southern Mozambique (P.C. Heemstra); D: SAIAB 95778, 148 mm SL, off Durban, South Africa (D. Hayes). The horizontal size bars indicate 20 mm length.

Figure 3. – Right otolith of Neobythites kenyaensis, SAIAB 98891, 121 mm SL (M. Krag).

Figure 4. – Radiograph of Neobythites kenyaensis, SAIAB 98890, 102 mm SL (M. Lisher). Inverted colour version on bottom.

Figure 5. – Quantitative otolith characters in Neobythites kenyaensis plotted against SL.

Figure 6. – Number of dorsal-fin rays in central ocellus spot plotted against latitude and depth in Neobythites kenyaensis. Numbers near symbols indicate multiple numbers of specimens referred to; with reference lines for each symbol.