taxonID	type	description	language	source
F3209B40CC67FFA0FF2A94B8FA8B848B.taxon	diagnosis	Diagnosis. Because of the significant increase of material (from four to 24 specimens) the generic diagnosis has been modified. Body elongate and compressed. Skin loose, transparent and scaleless. Pectoral peduncle as long as high with 23 – 27 fin rays. One short ray in each pelvic fin. Dorsal fin with 70 – 92, caudal fin with 7 – 9 and anal fin with 45 – 57 rays. Head broader and deeper than body. Mouth opening oblique ending in front of indistinct, deep-set eyes. Lower jaw slightly protruding. All teeth small and pointed; palatines edentate. Anterior gill arch with 20 – 27 small rakers of which 0 – 11 are slightly prolonged. Precaudal vertebrae 37 – 42 and total vertebrae 72 – 79. Vertebral centra in adults almost rectangular in lateral view and generally poorly ossified. Sagittal otolith small and semispherical. Females with a pair of claspers distally on urogenital hood. Males with penis more or less covered ventrally by urogenital hood; claspers not developed. Comparisons. Of the seven genera (see Nielsen 2015: Table 1) in the aphyonid clade of Bythitidae Nybelinella seems most similar to Barathronus Goode & Bean, 1886 and Meteoria Nielsen, 1969, with an oblique mouth opening and short pectoral peduncle. Nybelinella differs from Barathronus by having 20 – 27 short rakers on anterior gill arch (vs. 23 – 35 rakers, about five times as long) and vertebral centra rectangular in lateral view (vs. hour-glass shaped). From Meteoria it differs by having 20 – 27 short rakers on anterior gill arch (vs. no rakers), 23 – 27 pectoral fin rays (vs. 12 – 15 rays), one short pelvic fin ray (vs. no rays), more dorsal fin rays (70 – 92 vs. 47 – 58) and more anal fin rays (45 – 57 vs. 31 – 40).	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC67FFA0FF2A94B8FA8B848B.taxon	description	N. erikssoni N. brevianalis N. brevidorsalis	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC65FFA7FF2A9437FEC7840C.taxon	materials_examined	Material examined (22 specimens, SL 30 - 85 mm): Holotype: NHMG Pi. 1743, SL 75 mm, female, tropical East Atlantic, 01 ° 03 ’ N, 18 ° 40 ’ W, Swedish Deep-Sea Exped. st. 342, bottom trawl, 5250 – 5300 m, 16 July 1948. Nontypes: ZMUC P 77455, SL 70 mm, male, north of Madagascar, 05 ° 25 ’ S, 47 ° 09 ’ E, R / V Galathea, st. 274, herring otter trawl, 4820 m, 10 Mar. 1951. ZMH 26054, SL 57 mm, female, off NW Spain, 42 ° 38 ’ N, 13 ° 36 ’ W, R / V Meteor, st. 24, Agassiz Trawl, 5000 m, 16 Sep. 1968. MNHN 1979 - 231, SL 55 mm, male, Angola Basin, 27 ° 00 ’ S, 01 ° 06 ’ E, Campagne Walvis, st. C (CP 10), bottom trawl, 5211 m, 7 Jan. 1979. ZMUC P 77706 (former VIMS 05711), SL 78, female, Bahamas, 26 ° 03.3 ’ - 10.2 ’ N, 74 ° 03.2 ’ - 02.1 ’ W, R / V Columbus Iselin, cr. CI- 8007, st. C- 027, 45 ’ semi-balloon trawl, 5065 m, 10 Sep. 1980. BMNH 2016.7.29.1, SL 30 mm, male, SW of Azores Isls., 34 ° 58 ’ 6 ’’ N, 32 ° 56 ’ 30 ’’ W, R / V Discovery, st. 10379 # 37, 2960 – 2985 m, 16 June 1981. VIMS 34749, SL 73 mm, male, Bahamas, 23 ° 02 ’ N, 68 ° 24 ’ W, R / V Columbus Iselin, st. D- 018, 45 ’ otter trawl, 5303 – 5387 m, 25 Nov. 1981. VIMS 0 6618, SL 55 mm, female, Venezuela Basin, 13 ° 51.8 ’ - 45.5 ’ N, 67 ° 52.4 ’ - 46.2 ’ W, R / V Bartlett, cr. 1301 - 82, st. E- 065, 45 ’ otter trawl, 5000 m, 9 Nov. 1981. VIMS 0 6 619, SL 60, male, Venezuelan Basin, 14 ° 16.7 ’ - 21.9 ’ N, 67 ° 06.2 ’ - 66 ° 58.4 ’ W, R / V Bartlett, cr. 1301 - 82, st. E- 096, 45 ’ otter trawl, 5011 m, 30 Nov. / 1 Dec. 1981. ZMH 121802, SL 83 mm, female, off NW Spain, 45 ° 55 ’ N, 17 ° 10 ’ W, R / V Walther Herwig 2, Agassiz Trawl, 4640 m, 27 Apr. 1984. ZMH 119263, SL 76 mm, male, off NW Spain, 42 ° 23 ' N, 14 ° 31 ' W, R / V Walther Herwig 2, Agassiz Trawl, 5260 m, 3 May 1984. BMNH 2016.7.29.2 - 3, 2 specimens, SL 85 mm (female) and SL 39 mm (unripe), north of Madeira, 34 ° 45 ’ 42 ’’ N, 18 ° 30 ’ W, R / V Discovery, st. 11134 # 1, OTSB 14, 4790 – 4880 m, 10 June 1984. BMNH 2016.7. 29.8, SL 36 mm, male, SW of Madeira, 31 ° 12 ’ 48 ’’ N, 25 ° 18 ’ 18 ’’ W, R / V Discovery, st. 11261 # 50, OTSB, 5440 m, 2 July 1985. BMNH 2016.7.29.4 - 7, 4 specimens, SL 45 – 68 mm, SW of Madeira, 31 ° 7 ’ N, 25 ° 5 ’ 12 ’’ W, R / V Discovery, st. 11261 # 44, OTSB, 5440 m, 1 Aug. 1985. BMNH 2016.7. 29.9, SL 60 mm, SW of Madeira, 31 ° 12 ’ 36 ’’ N, 25 ° 12 ’ 30 ’’ W, R / V Discovery, st. 11261 # 52, OTSB, 5440 m, 3 Aug. 1985. BMNH 1994.5. 9.7, SL 62 mm, female, SW of Madeira, 20 ° 55 ’ 58 ’’ N, 31 ° 11 ’ 29 ’’ W, R / V Discovery, st. 12600 # 66, OTSB, 4500 – 4610 m, 16 Oct. 1993. BMNH 2016.7. 29.10, SL 50 mm, female, off Madeira, 35 ° 39 ’ 30 ’’ N, 13 ° 41 ’ 20 ’’ W, R / V Challenger, st. 53603 # 2, OTSB, 4855 - 4861 m, 29 Sep. 1995. Tentatively referred specimen: BMNH 2016.7.29.12, SL 57 + mm, ripe female, off Western Sahara, 25 ° 33 ’ 36 ’’ N, 16 ° 40 ’ 6 ’’ W, R / V Discovery, st. 8682 # 5, 150 cm sledge, 3000 m, 7 Feb. 1975. A part of the caudal fin is missing so many of the meristic and morphometric characters are unobtainable. The remaining characters are typical for N. erikssoni except for the following: pectoral-fin rays 19 (vs. 23 – 27 in N. erikssoni) and rakers on anterior gill arch 20 (vs. 23 – 27) of which two are slightly prolonged (vs. 5 – 8). Additional material may settle the taxonomic position of the present specimen. Remarks on material. Ten of the 22 specimens here examined have been mentioned earlier in the literature, but for only three of these (NHMG Pi. 1743 (holotype), ZMUC P 77455 and ZMH 26054) a description was published while seven were merely listed by Merrett (1992) as caught abyssally in the eastern North Atlantic.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC65FFA7FF2A9437FEC7840C.taxon	diagnosis	Diagnosis. Nybelinella erikssoni is long, slender and compressed. Dorsal fin with 79 – 92 rays, anal fin with 51 – 57 rays and pectoral fin with 23 – 27 rays. Precaudal vertebrae 37 – 42, total vertebrae 75 – 79. Origin of anal fin below dorsal fin no. 29 – 40. Totally 23 – 27 small rakers on anterior gill arch with 3 – 4 on upper branch and lower branch with the dorsal 5 – 8 rakers slightly longer than the rest. Gill filaments very small. Predorsal 39.5 – 46.5 % SL and preanal 58 – 64 % SL. Comparisons. Nybelinella erikssoni differs from N. brevianalis by having more anal fin rays (51 – 57 vs. 45), totally 23 – 27 rakers on anterior gill arch (vs. 20), 5 – 8 slightly prolonged rakers dorsally on lower branch of anterior gill arch (vs. none) and preanal length shorter (58 – 64 % SL vs. 73 % SL). From N. brevidorsalis it differs by having more dorsal fin rays (79 – 92 vs. 70), origin of anal fin below dorsal fin no. 29 – 40 (vs. 19) and predorsal length 39.5 – 46.5 % SL (vs. 52).	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC65FFA7FF2A9437FEC7840C.taxon	description	Description. The principal meristic and morphometric characters are shown in Table 1 and for a thorough description of the holotype and ZMUC P 77455 see Nielsen (1969: 23). Body slender and head higher and broader than body. Skin loose, transparent and scaleless. Mouth oblique with protruding lower jaw. Eyes deep-set with a centrally placed pigmented part surrounded by a narrow black ring (diameter 1.5 – 2.3 % SL). Eyes of smaller specimens more densely pigmented and thus more distinct. Nostrils and head pores difficult to observe due to torn skin. Origin of dorsal fin well in front of midpoint of fish and origin of anal fin posterior to midpoint. One short ray in each pelvic fin placed below basis of pectoral fin. Anterior gill arch with 3 – 4 minute rakers on upper branch and lower branch with 20 – 24 small rakers of which the upper 5 - 8 are longer than the rest. Gill filaments extremely small (Fig. 3). Small, semi-spherical sagittal otoliths twice as long as thick and with a centrally placed, undivided sulcus (Fig. 4). Six of the females are ripe with dark brown eggs about 1 mm in diameter and two of them with free, about 10 mm long embryos (Fig. 5). Females with a pair of claspers posteriorly on urogenital sinus; median fold rarely intact (Fig. 6). Males with well-developed urogenital hood ventrally covering penis; claspers not developed (Fig. 7). Axial skeleton (Fig. 8). Number of precaudal vertebrae 37 – 42. Neural spine of anterior vertebra the longest with spine-length decreasing posteriorad. Parapophyses and ribs not developed except for a few specimens with a weak ventral process on the posterior 1 – 2 precaudal vertebral centra. All vertebral centra are almost rectrangular in lateral view. In a 30 mm SL specimen the highest precaudal vertebral centrum is seven times higher than long, in a 57 mm SL it is three times higher than long and in a 85 mm SL it is twice as high as long. Dentition. All teeth are very small, pointed and most of them retrorse. Premaxillaries and dentaries with 3 - 4 rows near the symphysis decreasing to one row further back and with the posterior third edentate. Vomer with 5 – 15 teeth medially and a few specimens with scattered teeth on the wings. Palatines edentate. Coloration. Head and body uniformly brown to light-brown. Comparison with photos of newly caught specimens shows that not much bleaching has taken place. Eye and surrounding ring black.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC65FFA7FF2A9437FEC7840C.taxon	distribution	Distribution (Fig. 1). Nybelinella erikssoni is caught in the North Atlantic except for two specimens from the southeastern Atlantic and north of Madagascar. They were caught in bottom fishing gear at depths between 2960 and 5440 m.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC61FFA7FF2A90AEFC0781E4.taxon	materials_examined	Material examined (1 specimen, SL 62 mm). Holotype: BMNH 2016.7. 29.11, SL 62 mm, female, west of Madeira, 31 ° 14.9 ’ N, 27 ° 7.5 ’ W, R / V Discovery, st. 12174 # 31, OTSB 14, 4914 – 4938 m, 20 Aug. 1990.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC61FFA7FF2A90AEFC0781E4.taxon	diagnosis	Diagnosis. Nybelinella brevianalis is long, slender and compressed. Dorsal fin with 81 rays, anal fin with 45 rays and pectoral fins with 25 rays. Totally 76 (42 + 3 4) vertebrae. Origin of anal fin below dorsal fin no. 33. Upper branch of anterior gill arch without rakers and lower branch with 20 equally sized, small rakers. Small teeth on vomer. All neural and haemal spines ovate-formed (see note to Key to Species). Predorsal 44.0 % SL and preanal 73 % SL. Comparisons. Nybelinella brevianalis differs from N. brevidorsalis and N. erikssoni by having fewer anal fin rays (45 vs. 50 - 57), no rakers on epibranchials (rakers present) and all neural and haemal spines ovate-formed (vs. all spines thin and pointed). From N. brevidorsalis it differs furthermore by having more dorsal fin rays (81 vs. 70), shorter predorsal length (44.0 vs. 52 % SL) and origin of anal fin below dorsal fin ray no. 33 (vs. 19) and from N. erikssoni it differs by a longer preanal length (73 % vs. 58 – 64 % SL).	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC61FFA7FF2A90AEFC0781E4.taxon	description	Description. The principal meristic and morphomorphic characters are shown in Table 1. Body elongate and slender. Head higher and broader than body. Skin loose, transparent and without scales. Lower jaw slightly protruding. Eyes small and deep-set with a centrally placed pigmented part (0.4 mm in diameter) surrounded by a narrow, black ring (1 mm in diameter). Nostrils and head pores very difficult to observe due to torn skin. Vertical fins joined. Origin of dorsal fin well in front of midpoint of fish. Origin of anal fin far behind midpoint of fish (preanal length 73 % SL). Pelvic fins, with one short ray in each, placed below basis of pectoral fins. Anterior gill arch without rakers on upper branch and lower branch with 20 equally sized, small rakers all provided with small denticles. Gill filaments extremely small. Length of distended ovaries 17 mm. Many fertilized eggs (1 mm in diameter) and several free embryos (10 mm long). Urogenital hood ends in a pair of torn claspers. Axial skeleton (Fig. 10). Number of precaudal vertebrae 42. All neural and haemal spines ovate-formed. Parapophyses and ribs not developed. The two vertebrae just in front of the anterior vertebra with an ovate haemal spine are provided with a short, thin ventral process; they are counted as the two posteriormost precaudal vertebrae. All vertebral centra almost rectangular in lateral view, twice as high as long. Dentition. All teeth small and pointed, some retrorse. Premaxillaries and dentaries with 3 – 4 rows anteriorly decreasing to one row posteriorly. Vomer with median patch of about 15 teeth. Palatines edentate. Coloration. After 26 years of preservation the fish is brownish except for the deep-set eyes which appear as a thin, black ring with a black center. The white liver and dark brown, ripe eggs are seen through the transparent peritoneum.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC61FFA7FF2A90AEFC0781E4.taxon	distribution	Distribution (Fig. 1). Known from one specimen trawled at abyssal depth (4914 – 4938 m) west of Madeira in the Northeast Atlantic Ocean.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC61FFA7FF2A90AEFC0781E4.taxon	etymology	Etymology. The specific name, brevianalis, refers to the short anal fin.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC60FFA9FF2A966CFDD1844B.taxon	materials_examined	Material examined (1 specimen, SL 52 mm). Holotype: ZISP 42297, SL 52 mm, male, southeastern India Ocean, 12 ° 47 ’ S, 88 ° 54 ’ E, R / V Vityaz, st. 6744 - 5, Sigsby trawl, 5160 m, 15 Mar. 1973.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC60FFA9FF2A966CFDD1844B.taxon	diagnosis	Diagnosis. Nybelinella brevidorsalis is long, slender and compressed with a downward bent head and a slightly protruding lower jaw. Dorsal fin with 70 rays, anal fin with 50 rays and pectoral fins with 27 rays. Totally 72 (37 + 35) vertebrae. Origin of anal fin below dorsal fin ray no. 19. Upper branch of anterior gill arch with short rakers; lower branch with shorter rakers dorsally than ventrally. Palatines and vomer edentate. Predorsal 52 % SL and preanal 65 % SL. Comparisons. Nybelinella brevidorsalis differs from N. brevianalis and N. erikssoni by having fewer dorsal fin rays (70 vs. 79 – 92), fewer vertebrae (72 vs. 75 – 79), origin of anal fin below dorsal fin ray no. 19 (vs. 29 – 40), predorsal length 52 % SL (vs. 39.5 – 46.5), no teeth on vomer (vs. small teeth on vomer) and by having longer rakers ventrally on lower branch of anterior gill arch (vs. longer rakers dorsally on lower branch in N. erikssoni and all rakers equal in length in N. brevianalis). Furthermore, N. brevidorsalis differs from N. brevianalis by having slender neural and haemal spines (vs. ovate-formed spines).	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC60FFA9FF2A966CFDD1844B.taxon	description	Description. The original description was published in Russian. The present description is based on a translation of the original description and examination of the holotype. The principal meristic and morphometric characters are shown in Table 1. Body long and slender and head higher and broader than body. Skin loose, transparent and without scales. Lower jaw slightly protruding. Black eyes small and deep-set with a black, surrounding ring. Vertical fins joined. Origin of dorsal fin just behind midpoint of fish. Anal fin origin far behind midpoint (preanal length 65 % SL). Anterior gill arch with four short rakers on upper branch and lower branch with seven short followed by 11 somewhat longer rakers on the lower part. Gill filaments very short. A radiograph shows a pair of sagittal otoliths 0.2 mm in diameter. Penis covered ventrally by well-developed urogenital hood. Axial skeleton (from radiographs). Number of precaudal vertebrae 37. All neural and haemal spines thin and pointed. Anterior neural spine longest and the spines gradually decreasing in length posteriorad. Parapophyses and ribs not developed. All vertebral centra almost rectangular in lateral view, being twice as high as long. Dentition. Teeth generally poorly developed. Palatines and vomer edentate. Premaxillaries and dentaries with small, pointed teeth. Coloration. After two years in formalin the specimen was yellowish with small cinnamon-brown pigment spots on body and at base of pectoral fin rays. A black ring surrounds the black eyes.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
F3209B40CC60FFA9FF2A966CFDD1844B.taxon	distribution	Distribution (Fig. 1). Nybelinella brevidorsalis is known from one specimen trawled at abyssal depth (5160 m) in the southeastern Indian Ocean.	en	Nielsen, Jørgen G. (2017): Revision of the genus Nybelinella (Teleostei, Bythitidae) with a new Atlantic, abyssal species. Zootaxa 4247 (1): 45-54, DOI: 10.11646/zootaxa.4247.1.4
