Nothobranchius kadleci, Reichard, Martin, 2010

Reichard, Martin, 2010, Nothobranchius kadleci (Cyprinodontiformes: Nothobranchiidae), a new species of annual killifish from central Mozambique, Zootaxa 2332, pp. 49-60 : 51-59

Nothobranchius kadleci , new species

Figs. 1 & 2 , Table 1

Holotype. ZMB 33909, male, 38.1 mm SL, Sofala Province, Mozambique, temporary pool about 100 m from the main EN1 national road, not connected to any permanent river system, 20° 41.3' S, 34° 0 6. 4' E (collection code MZCS 08/91), collected by Martin Reichard, Matej Polačik, Ondřej Sedláček, 18 February 2008.

Paratypes. ZMB 33910, female, 32.2 mm SL; MRAC 2009-12 -P-1, male, 40.2 mm SL; MRAC 2009-12 - P-2, female, 35.8 mm SL; NMP P 6 V 86687, male, 36.1 mm SL; NMP P 6 V 86688, female, 31.0 mm SL. All paratypes share same collection data as holotype.

Non-type material. MZCS-08/99, 3 males and 3 females, Pungwe River Basin, Sofala Province, Mozambique, 19° 17.4' S, 34° 13.8' E; MZCS-08/107, 5 males, border of Save and Gorongose River Basins, Sofala Province, Mozambique, 21° 00.9' S, 34° 27.8' E.

Diagnosis. Nothobranchius kadleci is distinguished from N. furzeri by the smaller depth of the dorsal fin (17.9–31.0 % SL vs. 27.4–37.7 % SL in N. furzeri in males, 14.9–17.6 % SL vs. 19.0–21.9 % SL in females) and smaller depth of the anal fin (17.4–25.8 % SL vs. 22.4–32.4 % SL in N. furzeri in males, 17.3–19.2 % SL vs. 19.3–24.5 % SL in females), larger preanal distance (64.0–65.8 % SL vs. 58.9–61.3 % SL in N. furzeri ) in females and presence of red colour on gill membrane and lips and red pectoral fins ( N. furzeri does not possess red colour on gill membrane and lips and typically have yellow pectoral fins), absence of black marginal band on caudal fin (present in some male N. furzeri ), and a higher amount of red on caudal and dorsal fins and on body in males.

It is distinguished from sympatric N. orthonotus (including putative N. kuhntae and N. mayeri ) by the shape of the frontal region (convex in N. kadleci , flat in N. orthonotus ), the presence of red pectoral fins with white margins, often with a bluish tint ( N. orthonotus possess transparent or whitish pectoral fins with red margins), red background colour on the head covered with small to large light blue marking ( N. orthonotus possess red spots on white to grey background colour of the head and, in most populations, also on anterior ventral part of the body), shorter preanal distance (range 58.4–61.2 % SL vs. 62.7–72.5 % SL in N. orthonotus ), and distance between pelvic and anal fins (10.2–13.5 % SL vs. 13.4–16.6 % SL) in males.

Nothobranchius kadleci differs from sympatric N. rachovii in males by a lack of black margin of the caudal fin, distance between pectoral and pelvic fins (15.1–21.7 % SL vs. 12.8–16.7 % SL in N. rachovii ), minimal body depth (15.0–16.9 % SL vs. 13.5–15.4 % SL) and eye diameter (22.1–27.3 % HL vs. 26.0–32.6 % HL) and in females by preanal distance (64.0–65.8 % SL vs. 61.8–64.5 % SL), length of caudal peduncle (20.1–21.6 % SL vs. 13.4–20.1 % SL), depth of dorsal fin (14.9–17.6 % SL vs. 16.8–23.2 % SL), and depth of anal fin (17.3–19.2 % SL vs. 21.0–23.2 % SL).

Description. Morphology and general body shape similar to N. furzeri ( Figs. 1 & 2 , Table 1 ). A robust Nothobranchius species with a characteristic convex frontal region, in mature males sometimes exaggerated into a distinctive frontal hump. The dorsal fin 13–14 rays, anal fin 13–14 rays (up to 16 in females), pelvic fin 6 rays and pectoral fin 16–18 rays. In males, pectoral fins typically overlap with pelvic fins (50 % of the pectoral fin is beyond the anterior margin of pelvic fin). Pelvic fins reach or slightly overlap the base of the anal fin. The longest rays of dorsal and anal fins reach or extend beyond the anterior margin of the caudal fin. In females, the longest rays of the pelvic fin just reach the anal fin base. About 30 % of the pectoral fin extends beyond the base of the pelvic fin. The tip of female anal fin does not reach the caudal fin, but the dorsal fin sometimes reaches the caudal fin. The longitudinal series possesses 27–29 scales; one large male (50.2 mm SL) with 34 scales in the longitudinal series was recorded.

Live colouration. Males. Colouration varies from deep red to light blue and appears to be continuous rather than falling into two discrete colour forms ( Figs. 2 & 3 ). Fully red males have an entirely red caudal fin. The dorsal fin is red with a narrow white margin and white (over the entire fin) or yellow (in the anterior 1/3 of the fin) irregular dots and lines on the fin membrane. The anal fin is red with a narrow white margin and white dots or lines, though white marking is less developed than in the dorsal fin. Pectoral fins are red with white or light blue tips. Ventral fins are red, sometimes with traces of white marking. The body is red, including the head, lips and gill membrane. Scales have large light blue centres, giving an impression of a reticulated pattern on the entire body. In blue males, the base colour of the fins is also red, but light blue (or sometimes whitish) dots and lines are abundant on all fins except for the pectoral fins (which are always red in wild, sexually mature males, though red colour may be less developed in subadult males). In blue males, especially subadult specimens, light blue marking on the body covers a large extent of the red, including a large area of the head. The eyes of all males are orange to gold with a dark vertical band.

Females. All fins are transparent. A slight yellowish tint may be present on the distal part of the dorsal and anal fins. The body is light yellow to light brown, with the posterior part of scales shining an iridescent light blue. Sometimes (<10 % of specimens), small black dots appear on the body. The eye is orange to gold, with a black vertical band.

Colouration in preservative. After one year of preservation in 4 % formaldehyde solution, male colouration was yellow to light brown (similar to live colouration of females), and the pelvic part whitish ( Fig. 1A ). Black marking is present on the opercular region, gill membrane and distal part of dorsal fin of some individuals (including the holotype). Small black dots are present on the caudal and dorsal fins. The anal, pelvic and pectoral fins are orange. Female body colouration is identical and fins are transparent. Rarely, the black dots are visible.

Males Females

Distribution. This new species was found in 12 populations from a relatively large area in central Mozambique, north of the Save River, including the basin of the Save, Gorongose, Pungwe and Zangue Rivers ( Fig. 4 , Table 2 ). The altitude of collections sites ranged from 24–82 m above sea level. The latitudinal extent of the range of N. kadleci is over 300 km primarily along the north-south axis.

Habitats. All populations of N. kadleci were found in small temporary pools varying from 3.5– 2150 m 2, with a maximum depth of 10–70 cm in 2008 and 50 –100 cm in 2009, very turbid water and soft muddy bottom ( Fig. 5 , Table 2 ). Littoral vegetation was present in 50 % of the pools, with scarce Nymphaea sp. vegetation in two pools. Conductivity ranged from 68–300 ΜS.cm-2 and water temperature during collection was 27.7–38.2 °C. Sympatric fish species included N. orthonotus (10 cases), N. rachovii (2 cases), an unidentified small Barbus sp. (2 cases), Tilapia sp. (1 case), Protopterus sp. (1 case) and Clarias gariepinus (1 case).

Etymology. The species is named in honour of the late Jaroslav Kadlec (1951–2006) from Brno, Czech Republic, a renowned killifish breeder recognized worldwide for his articles on killifish breeding, ecology, and his photographs. To be pronounced “khadlatsi”.

Latitude Longitude Altitude Conductivity Temperature Max. depth Sympatric species

(masl) (ΜS. cm -2) (°C) (cm)

MZCS 08/91* 20° 41.3' S 34° 06.4' E 62 300 38.2 10

MZCS 08/92 19 ° 19.6' S 34° 18.5' E 24 173 33.5 50

The external morphology of Nothobranchius kadleci is similar to that of N. furzeri , but the two species clearly differ in their colouration ( Figs. 2 & 3 ) and have apparently allopatric distribution. Many Nothobranchius species, including N. furzeri , occur in two distinct colour morphs. In other Nothobranchius species, more continuous colour variation is found ( Wildekamp 2004). This appears to be the case in N. kadleci , with a continuous variation from fully red males with some light blue markings on body and fins to males with a larger extent of blue on their body and fins. Additionally, the amount of red also appears to increase with the age of the fish. Some female N. kadleci have irregular black dots on their bodies (especially at MZCS-08/107, but also MZCS-08/91) which is characteristic for some populations of N. orthonotus (especially in vicinity of the city of Beira), but lacking in all known N. furzeri populations.

The Save River forms an apparent range boundary between N. kadleci (north of the Save) and N. furzeri (south of the Save). This is confirmed by a thorough sampling effort ( Wood 2000; Terzibasi et al. 2008; Reichard et al. 2009). The species status is supported by the analysis of mitochondrial and nuclear DNA markers (Reichard et al., unpublished data), with N. kadleci being a sister species of N. furzeri .

Two populations of Nothobranchius kadleci were imported and are bred in the aquarium facilities of the Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, and distributed among dedicated killifish breeders under the names Nothobranchius sp. aff. furzeri MZCS-08/91 Gorongose and Nothobranchius sp. aff. furzeri MZCS-08/108 Save. It should be noted that the fish described here as N. kadleci was collected in central Mozambique in May 1970 on the floodplain of the Pungwe River by D.

Plowes (R. Wildekamp, personal communication) and in 1973 in the vicinity of the town Vila Machado (now Nhamatanda) in the Pungwe River basin by D. G. Donnelly (B. Watters, personal communication). It has never been recollected and it was regarded as a very red colour form of N. orthonotus (known as Nothobranchius sp. Vila Machado) (B. Watters, personal communication). All subsequent collections in the area were performed in April or May after the cessation of the rainy season. In contrast, our sampling was carried out in February (during the rainy season). It is possible that, similar to N. furzeri , N. kadleci is a shortlived species inhabiting shallow pools that desiccate earlier than those inhabited by other Nothobranchius species in the area. Indeed, within the same site N. kadleci were often found in shallower pools, while adjacent (<10 m) deeper pools were inhabited by N. orthonotus and N. rachovii . At other sites, all three species were syntopic at the time of collection. Nothobranchius kadleci has never been recorded in lowland floodplains (such as in the vicinity of Beira).

In conclusion, N. kadleci may be a short-lived rather than rare species and occurs in a range of small temporary pools between the Save and Zambezi River. It is expected that it might play an important role in the comparative research on aging where N. furzeri (from drier regions than N. kadleci ) is becoming a model species due to its short lifespan ( Valdesalici & Cellerino 2003; Genade et al. 2005; Terzibasi et al. 2007; Terzibasi et al. 2008)

Figures

FIGURE 2. Adult males of N. kadleci photographed in the wild (A – C) and in aquarium 1 – 2 months after capture (D – F). Males are either of red form (left panel) or blue form (right panel). Note a distinct frontal hump on male pictured at photograph (C). Individual on panel (D) is a subadult and has yet not fully developed colouration. Panels (A) and (E) show the same individual in the field and in aquarium. Photos by O. Sedláċek (A, B, D, E & F), and R. Blažek (C).

FIGURE 3. Comparison of adult N. kadleci with related species; (A) male N. kadleci (left) with allopatric male N. orthonotus from Beira region (right), (B) female N. kadleci (lower) with sympatric female N. orthonotus (upper), (C) male N. kadleci (lower) with sympatric male N. orthonotus (upper) and (D) male N. rachovii, a species sympatric with N. kadleci. Allopatric N. furzeri male of (E) red form and (F) yellow form. Photos by O. Sedláċek.

FIGURE 4. Distribution of N. kadleci and N. furzeri. Populations recorded in February 2008 and February 2009 are denoted, with type localities encircled. Some marks may represent several adjacent populations. Type locality of N. furzeri according to Jubb (1971).

FIGURE 5. Habitat of N. kadleci; (A) type locality MZCS- 08 / 91 (Gorongose River basin), (B) MZCS- 08 / 107 (Save River basin) and (C) MZCS- 08 / 99 (Pungwe River basin), all sites in central Mozambique, Sofala Province. Photos by O. Sedláċek.

FIGURE 1. A. Nothobranchius kadleci, holotype, adult male, 38.5 mm SL, ZMB 33909 (upper fish) and paratype, adult female, 32.8 mm SL, ZMB 33910 (lower fish) from Mozambique, Sofala Province, isolated savannah pool in the Gorongose River drainage, stored in 4 % formaldehyde for one year. B. Adult male N. kadleci with a frontal bump (upper fish) and sympatric N. orthonotus male (lower fish). Note the difference in head and body shape.

Tables

TABLE 1. Morphometric measurements of N. kadleci and N. furzeri. Standard length and head length are given, with other variables expressed as a percentage of standard and head lengths, respectively. Measurements taken on male N. kadleci (including holotype for which the value is given separately) and male N. furzeri were tested using a t - test. Characters that were significantly different between N. kadleci and N. furzeri (P <0.05) are marked by an asterisk.

	Holotype	N. kadleci (N=10)	N. furzeri (N=10)	N. kadleci (N=3)	N. furzeri (N=3)
SL (mm)	38.5	43.3 38.5 -50.2	43.1 36.1 -47.5	31.3 -34.6	31.0 -35.8
In % of standard length
total length	121.8	124.2 120.3 -127.9	123.7 119.7 -128.2	121.7 -124.1	119.9 -123.9
head length	34.5	33.8 31.7 -36.2	34.7 31.4 -37.7	29.4 -33.2	31.8 -34.5
predorsal distance	56.4	59.7 56.1 -61.7	60.4 57.3 -63.2	59.7 -62.8	59.5 -62.6
preanal distance	60.3	59.7 58.4 -61.2	59.9 57.3 -61.9	64.0 -65.8	58.9 -61.3
preventral distance	49.9	50.1 46.7 -63.8	48.3 47.1 -51.2	46.6 -52.7	45.8 -48.4
pectoral-pelvic distance*	15.1	16.9 15.1 -21.7	15.0 13.7 -17.7	15.9 -20.7	16.5 -18.7
pectoral-ventral distance	12.2	11.6 10.2 -13.5	12.2 11.2 -13.4	13.6 -16.0	12.3 -21.6
length of anal fin base*	21.8	20.8 18.1 -23.0	22.3 19.7 -24.8	0.0 -19.4	17.1 -19.3
length of dorsal fin base	25.5	25.3 22.5 -27.2	26.0 23.9 -28.0	17.9 -24.9	23.6 -24.9
maximum body depth	28.6	30.0 27.1 -31.9	29.1 26.9 -31.0	23.3 -29.8	23.6 -25.8
depth of caudal peduncle	15.1	16.4 15.1 -17.1	16.3 13.7 -21.5	14.1 -14.9	14.2 -16.1
length of caudal peduncle	16.1	20.1 16.1 -23.7	17.9 13.0 -21.1	20.1 -21.6	0.0 -22.6
minimum body depth	15.1	15.9 15.0 -16.9	15.3 13.7 -16.5	13.1 -14.0	12.6 -13.7
length of caudal fin	21.3	23.0 19.5 -27.1	22.7 18.4 -25.1	22.0 -23.1	19.0 -21.3
depth of dorsal fin*	17.9	25.5 17.9 -31.0	30.8 27.4 -37.7	14.9 -17.6	19.0 -21.9
depth of anal fin *	17.4	21.4 17.4 -25.8	25.7 22.4 -32.4	17.3 -19.2	19.3 -24.5
Head length (mm)	13.3	14.6 13.0 -17.2	15.9 13.0 -26.5	9.2 -11.3	10.7 -11.4
In % of head length
preorbital distance	26.3	27.7 21.2 -32.6	26.5 23.8 -29.6	22.9 -26.1	19.6 -23.7
postorbital distance	48.9	51.4 47.7 -55.4	52.2 47.3 -58.7	50.0 -52.3	46.7 -47.4
eye diameter	23.3	24.5 22.1 -27.3	26.3 21.4 -58.0	23.9 -29.3	26.2 -28.1
interorbital distance	43.6	47.2 43.6 -52.4	47.2 44.1 -53.2	43.1 -51.1	37.4 -49.1
head depth	78.2	85.5 78.2 -102.1	80.1 71.5 -87.9	76.1 -87.0	69.2 -78.1

TABLE 2. Geographic coordinates and habitat characteristics of 12 sites with N. kadleci researched during the 2008 and 2009 MZCS expeditions.

MZCS 08/99 19° 17.4' S 34° 13.8' E 47	220	33.5	75	N. orthonotus , Clarias gariepinus , Barbus sp.
MZCS 08/107 21° 00.9' S 34° 27.8' E 79	77	30	25	N. orthonotus
MZCS 08/108 21° 00.7' S 34° 32.2' E 73	100	32.6	50	N. orthonotus , N. rachovii
MZCS 08/109 21° 00.4' S 34° 32.4' E 82	91	33	25	N. orthonotus
MZCS 08/110 20° 59.9' S 34° 35.3' E 68	97	34	30	N. orthonotus
MZCS 08/112 21° 01.7' S 34° 44.7' E 28	109	33.1	40	N. orthonotus
MZCS 09/40 18° 06.2' S 34° 43.8' E 82	250	28.5	50	N. orthonotus
MZCS 09/62 18° 08.0' S 35° 01.4' E 39	199	27.7	80	N. orthonotus
MZCS 09/67 20° 44.4' S 34° 08.7' E 58	68	29	90	N. orthonotus
MZCS 09/68 20° 44.4' S 34° 08.7' E 58	99	28.9	100	N. orthonotus , N. rachovii , Barbus sp., Tilapia sp., Protopterus sp.
*type locality.
Discussion