The description of a critically endangered new species of seasonal killifish, Nothobranchius sylvaticus (Cyprinodontiformes: Nothobranchiidae), a relict species from an East African forest refugium in south-eastern Kenya Author Bellstedt, Dirk U. Department of Biochemistry, Stellenbosch University, South Africa. Author Nagy, Béla 0000-0003-4718-0822 15, voie de la Liberté, 77870 Vulaines sur Seine, France. bela.nagy@neuf.fr Author Merwe, P. De Wet Van Der 0000-0001-9315-599X Department of Biochemistry, Stellenbosch University, South Africa. pdew@sun.ac.za Author Cotterill, Fenton P. D. 0000-0003-4561-018X The Wilderness Project-Great Spine of Africa, Wild Bird Trust, Johannesburg, South Africa. fcotterill@gmail.com Author Luke, Quentin 0000-0002-7256-031X East African Herbarium, National Museums of Kenya, PO Box 45166, Nairobi 00100, Kenya. quentinluke1@gmail.com Author Watters, Brian R. 0000-0002-7651-6500 6141 Parkwood Drive, Nanaimo, British Columbia V 9 T 6 A 2, Canada. bwatters@shaw.ca text Zootaxa 2025 2025-03-06 5601 1 86 108 https://doi.org/10.11646/zootaxa.5601.1.4 journal article 308543 10.11646/zootaxa.5601.1.4 d1789817-5b79-4e53-9978-87a96666f1e3 1175-5326 14980503 8A11A5A0-23D7-4DEA-9FFC-4C2989B96D2C

TABLE 1. Morphometric and meristic data for holotype and paratypes of Nothobranchius sylvaticus. Holotype values included in ranges, mean and standard deviation of males. H, holotype; SD, standard deviation.

	males				females
included in ranges, mean and standard deviation of males. H, holotype; SD, standard deviation.
	(n = 5)				(n = 4)
	H	range	mean	SD	range	mean	SD
Standard length	33.6	29.2–34.3			25.2–26.5
Percent of standard length
Total length	125.6	123.1–127.1	125.5	1.5	129.8–131.3	130.6	0.6
Body depth at pelvic–fin origin	27.7	26.4–27.9	27.2	0.6	25.3–27.0	25.8	0.8
Head length	28.6	27.0–29.6	28.6	1.0	27.3–31.1	29.2	1.9
Preanal length	61.0	61.0–61.8	61.5	0.3	62.5–64.2	63.2	0.8
Predorsal length	57.7	57.7–60.3	59.3	1.0	61.1–62.6	61.7	0.7
Prepelvic length	48.8	46.2–49.4	48.2	1.2	48.0–52.1	49.8	1.7
Prepectoral length	29.8	27.3–30.8	29.7	1.4	28.3–32.3	30.0	1.9
Caudal peduncle length	22.3	20.7–22.3	21.6	0.6	21.8–23.0	22.5	0.5
Caudal peduncle depth	14.3	13.1–14.3	13.7	0.5	12.8–13.6	13.3	0.3
Dorsal-fin base length	26.5	23.4–26.5	24.7	1.6	20.0–23.0	21.4	1.3
Anal-fin base length	18.5	16.5–18.6	17.8	0.9	14.8–16.0	15.2	0.5
Caudal-fin length	25.6	23.1–27.1	25.5	1.5	29.8–31.3	30.6	0.6
Percent of head length
Head width	58,0	58–62	60.6	1.3	60–64	61.9	1.8
Head depth	79,0	75–79	77.5	1.6	76–79	78.1	1.3
Interorbital width	44	44–50	46.6	2.9	44–49	46.2	2.1
Postorbital length	59	57–61	58.7	2.0	56–59	57.5	1.2
Suborbital depth	19	19–22	20.4	1.4	11–17	14.0	2.4
Eye diameter	29	28–32	30.7	1.8	28–31	30.0	1.8
Snout to eye end length	41	39–44	41.3	2.0	41–44	42.5	1.2
Snout length	14	14–19	16.1	2.0	14–15	14.6	0.4
Ratios
Head width in % of its depth	74	74–81	78.2	2.8	77–82	79.2	2.0
Caudal peduncle length in % of its depth	156	155–160	157.1	2.0	167–171	169.4	1.9
Meristics		range	mode		range	mode
Dorsal-fin rays	14	14–15	15		14–14	14
Anal-fin rays	13	13–15	13		13–13	13
Scales mid-longitudinal series	28	27–28	28		28–29	28
Scales transverse	11	11–11	11		11–11	11
Scales circumpeduncular	14	14–14	14		12–12	12