THE NOTHOBRANCHIUS SITE

MRAC 79-007-P-172, male, 41.5 mm SL; Kenya: Kwale: Ramisi River drainage: Kikoneni-Mrima road, 04°28'26" S, 39°17'05" E, about 75 m asl; E. Holler, Aug. 1978.

MRAC 79-007-P-173-180 (8)

Nothobranchius kwalensis is distinguished from all other congeners of the N. melanospilus complex by the combination of the following morphological character states: lower jaw not anteriorly projecting (vs. anteriorly projecting in N. prognathus); dorsal-fin origin anterior to anal-fin origin in females (vs. posterior in both sexes, in N. melanospilus); pelvic fins medially in contact (vs. bases medially united in males of N. prognathus); presence of two longitudinal series of scales on frontal region (vs. three in N. prognathus); anterior supraorbital series of neuromasts divided in two sections (vs. arranged in a single continuous row in N. melanospilus); mandibular neuromasts 14–16 (vs. 17–21 in N. melanospilus); in females, few rounded black dots on anterior portion of flank (vs. dots absent on anterior portion of flank in N. melanospilus); body depth 28.7–30.9 % SL in males, 25.8 % SL in female (vs. 32.7–35.5 and 32.1–33.4 % SL, respectively, in N. prognathus); dorsal-fin base length 24.1–27.3 % SL in males (vs. 27.9–29.9 % SL in N. prognathus); hed depth 79.0–82.9 % of head length in males, 69.5 % in female (vs. 90.4–99.2 and 85.6–90.3 % of head length, respectively, in N. prognathus); eye diameter 26.8–28.4 of head length in males, 27.1 % in female (vs. 20.9–25.9 % and 21.1–24.4 %, respectively, in N. prognathous) (Costa, 2019).

Subgenus: Adiniops

Species group: N. melanospilus group

Following its discovery in 1974, populations of this species found in the Ramisi drainage in southern Kenya were referred to N. melanospilus, a geographically widespread and locally common species in lowland East Africa, based on general similarities with that species. Based on morphological analyses and minor colour pattern differences, Costa (2019) separated two cryptic species from peripheral parts of the range of N. melanospilus, thus describing specimens from one location in Ramisi drainage in southern Kenya as N. kwalensis. Its status is currently controversial, sometimes regarded as colour variation and junior synonym of N. melanospilus.

Kenya: Kwale: Ramisi River drainage: Kikoneni-Mrima road, 04°28'26" S, 39°17'05" E.

This species is endemic to south-eastern coastal Kenya. It is known from seasonal pools and swamps in the Ramisi, Mwena and Umba drainages, in the coastal plain of south-eastern Kenya.

Tana, Athi, and Coastal drainages (567)

6–71 m

Personal observation at collecting sites (6 locations):

Water temperature: 24.6–32.5 °C (average: 28.2 °C)

pH: 6.5–8.0 (average: 7.3)

TDS:  53–1146 ppm (average: 414 ppm)

Conductivity: 106–2292 µS (average: 829 µS)

N. palmqvisti - 62%

This species has a semi-annual life cycle.​​

Embryonic development under captive conditions in peat moss is about two to four months at room temperature.

Maximum size reported: 41.5 mm SL; MRAC 79-007-P-172, holotype, male, (Costa, 2019)

Not known

The specific name is an allusion to the occurrence of the new species in the county of Kwala, Coastal Province of Kenya.

Endangered B1ab(iii)+2ab(iii) (Nagy & Watters, 2021)

    Walpole, M. 1975. A visit to east Africa in search of the genus Nothobranchius, Killi-News. British Killifish Association, (124): 1–6 & (125): 1–3. [collecting as Nothobranchius sp. Olago]

    Nagy, B. 2007. Collecting Nothobranchius - My special souvenir from Kenya 2007. Journal of the American Killifish Association, 40 (4): 97–113. [collecting as N. melanospilus]

    Costa, W. J. E. M. 2019. Two new species of seasonal killifishes of the Nothobranchius melanospilus species complex from the East Africa biodiversity hotspot (Cyprinodontiformes: Aplocheilidae). Vertebrate Zoology, 69 (1): 73–82. [taxonomy as Nothobranchius kwalensis]

    Watters, B. R., B. Nagy, P. D. W. van der Merwe, F. P. D. Cotterill & D. U. Bellstedt. 2019. Review of the Nothobranchius taeniopygus species group from central and western Tanzania with descriptions of five new species and redescription of Nothobranchius taeniopygus (Teleostei: Nothobranchiidae). Ichthyological Exploration of Freshwaters, IEF-1110, pp. 1–41. [phylogeny as N. melanospilus]

    Bartáková, V., B. Nagy, M. Polačik, R. Blažek, H. Lamtane & M. Reichard. 2020. Genetic diversity of a widespread annual killifish from coastal Tanzania. BMC Evolutionary Biology, 20: 1, 13 pp. [genetics]

    Nagy, B. & B. R. Watters. 2021. Nothobranchius kwalensis. The IUCN Red List of Threatened Species: e.T158619819A158619885. [conservation]