Devario memorialis Sudasinghe, Pethiyagoda & Meegaskumbura, 2020 a

Sudasinghe, Hiranya, Pethiyagoda, Rohan & Meegaskumbura, Madhava, 2025, Species without borders: the diversification of giant danios in Sri Lanka (Teleostei, Danionidae, Devario), Evolutionary Systematics 9 (2), pp. 229-258 : 229-258

Devario memorialis Sudasinghe, Pethiyagoda & Meegaskumbura, 2020 a

Devario memorialis Sudasinghe, Pethiyagoda & Meegaskumbura, 2020 a .

Material examined.

10 ex., see Suppl. material 1.

Diagnosis.

Devario memorialis is distinguished from its Sri Lankan congeners by the combination of the following characters and character states: anal-fin origin on vertical through dorsal-fin origin (vs anal-fin origin posterior to dorsal-fin origin, beneath 3 rd branched dorsal-fin ray in D. malabaricus , D. micronema , D. altus , and D. pathirana ); 1 st infraorbital smooth, with no infraorbital process (vs infraorbital process present in D. micronema , D. pathirana , and most specimens of D. altus ); anterior bars on body absent or indistinct (vs present in D. malabaricus , D. micronema , and D. pathirana ); preanal length 58.5–63.8 % SL (vs 64.9–69.8 % SL in D. pathirana ); caudal peduncle depth 8.1–9.8 % SL (vs 9.8–12.9 % SL in D. malabaricus , 11.3–13.1 % SL in D. pathirana ); body depth 15.9–22.6 % SL (vs 26.1–35.4 % SL in D. malabaricus , 23.5–36.6 % SL in D. micronema , 21.8–26.0 % SL in D. altus , 32.4–36.9 % SL in D. pathirana ); dorsal-fin height 15.7–20.0 % SL (vs 19.0–23.2 % SL in D. altus , 20.6–24.3 % SL in D. pathirana ); dorsal-fin base length 13.5–16.3 % SL (vs 16.7–23.5 % SL in D. malabaricus , 16.6–23.3 % SL in D. micronema , 19.0–23.8 % SL in D. pathirana ); anal-fin base length 20.0–23.4 % SL (vs 16.4–20.5 % SL in D. altus ); pelvic-fin height 11.6–13.3 % SL (vs 13.3–18.1 % SL in D. malabaricus , 13.8–18.5 % SL in D. micronema , 12.9–16.6 % SL in D. altus , 16.1–18.8 % SL in D. pathirana ); pectoral-fin height 19.1–23.6 % SL (vs 23.8–27.9 % SL in D. pathirana ); head depth 14.1–15.8 % SL (vs 16.0–23.0 % SL in D. micronema , 17.3–19.6 % SL in D. altus , 17.6–21.7 % SL in D. pathirana ); interorbital width 37.2–40.7 % HL (vs 40.7–45.3 % HL in D. pathirana ); rostral barbel 4.0–8.9 % HL (vs 8.3–14.2 % HL in D. altus , 8.6–17.7 % HL in D. pathirana ); 38–46 lateral-line scales (vs 33–39 in D. malabaricus ); predorsal scales 17–19 (vs 14–18 in D. malabaricus , 13–17 in D. micronema , 14–15 in D. pathirana ); 15–18 circumpeduncular scales (vs 12–15 in D. malabaricus , D. micronema , 13–14 in D. altus , D. pathirana ); 7 ½ scales between lateral line and dorsal-fin origin (vs 7 ½ – 9 in D. malabaricus , 7 ½ – 9 ½ in D. micronema , 6–7 ½ in D. altus , 8–8 ½ in D. pathirana ); 8 ½ branched dorsal-fin rays (vs 9 ½ – 12 ½ in D. malabaricus , D. micronema , 8 ½ – 10 ½ in D. altus , 11 ½ in D. pathirana ); 14 ½ – 15 ½ branched anal-fin rays (vs 13 ½ – 14 ½ in D. pathirana ).

Devario memorialis is genetically distinct from the remaining Sri Lankan species of Devario by an uncorrected p-distance of more than 3.9 % in the cox 1 DNA barcoding marker.

Habitat and distribution.

Devario memorialis has been recorded only from a 3 - kilometer section of a headwater tributary of the Ma Oya (river) near Aranayake, at an elevation of 238–266 m above sea level. This species typically inhabits the fast-flowing sections of the stream.

Remarks.

At some of the sampling sites at Aranayake, D. malabaricus occurs in syntopy with D. memorialis but at a lower frequency than the latter. All the specimens dissected to establish sex were females. Pectoral-fin tuberculation is absent in all the specimens in our series: it is possible that pectoral-fin tuberculation is absent in both sexes of D. memorialis .