THE NOTHOBRANCHIUS SITE

RMCA 2021.011.P.0001, male, 26.5 mm SL; Tanzania: Lake Victoria basin: ephemeral swamp about 3.5 km west of Kiziramiaga township, 2.155611 S, 31.632500 E; B. Nagy, K. Østergaard & G. Petneházy, 31 May 2019
[field code: TZN 19-4].

RMCA 2021.011.P.0006–7 (8)

Lacustricola margaritatus is a small species with a moderately deep body, moderate dimorphism and pronounced dichromatism. It is distinguished from all other Procatopodidae by the following unique combination of characters: live male body colour pattern with vertically-elongated iridescent light blue patches at scale centres, forming a striped appearance of dotted longitudinal lines on the flanks, particularly evident in the two or three series below the mid-longitudinal line; male having deeply coloured unpaired fins with orange-brown in the proximal and median parts and a narrow black distal band; male with a yellow base along the pectoral fin; female with dark grey scale margins and dark grey patches on scales along mid-longitudinal series creating a narrow dark grey stripe; both sexes showing inconspicuous postopercular blotch; and in both sexes, the cephalic sensory system is entirely situated in open grooves at all levels.

subgenus: Lacustricola sensu stricto

Population of this species from the Lake Victoria and Lake Kyoga basins were referred either to undescribed species or often regarded conspecific with L. pumilus known from Lake Tanganyika basin or 'L.' centralis from Lake Rukwa basin. However, it differs from the latter two species by morphometric and meristic characters, body and fin colouration, and in arrangement of the cephalic sensory system, as well as genetically.

Lacustricola margaritatus was established as a species by Nagy & Watters in 2022, based on morphometric and meristic characters, body and fin colouration, and arrangements of the cephalic sensory system.

Molecular analysis carried out by Bragança (pers. comm.) retrieved the species as a separate lineage within the genus Lacustricola (sensu stricto).

Tanzania: Lake Victoria basin: ephemeral swamp about 3.5 km west of Kiziramiaga township, 2.155611 S, 31.632500 E.

Lacustricola margaritatus is currently known from streams and swamps in the Lake Victoria basin in north-western Tanzania, south-western Kenya and southern Uganda, and in the Lake Kyoga basin in central Uganda. Known occurrences are restricted to the Lake Victoria ecoregion.

1048–1360 m

At the type locality, the water was turbid, the bottom of the pool was not visible. The water temperature around noon was 27.4° C, the pH was 7.8 and it contained 120 ppm of total dissolved solids.

Water parameters at nine different sites throughout the range of distribution measured by Watters & Nagy between 1999 and 2021, were as follows: temperature of 20.0–27.4 °C; pH of 7.3–7.8; conductivity of 40–240 μS.

Lacustricola bukobanus

Eggs develop in about two weeks at room temperature.

Maximum size reported: 28.0 mm SL (RMCA 2021.011.P.0005, paratype, male)

Not known

The specific name margaritatus is a Latin participial adjective meaning “adorned with pearls”, referring to the striped colour pattern of distinct pearlescent patches along the longitudinal series on the side of body.

Least Concern (Nagy & Watters, 2022).

Recommended as Least Concern (Nagy & Watters, 2022).

    Nagy, B. (2020) An Expedition Around Lake Victoria. Tropical Fish Hobbyist, #744, Sep/Oct 2020, 69 (1), 44–50. [collecting]   

    Nagy, B. & B. R. Watters. 2022. Lacustricola margaritatus, a new species of lampeye from the Lake Victoria and Lake Kyoga basins in eastern Africa (Cyprinodontiformes: Procatopodidae). Zootaxa 5128 (1): 044–060, https://doi.org/10.11646/zootaxa.5128.1.2 [taxonomy as  Lacustricola margaritatus]

    Nagy, B. & B. R. Watters. 2022. Lacustricola margaritatus. The IUCN Red List of Threatened Species: e.T219176408A219176412. [conservation]