A new highly apomorphic species of Bujurquina (Teleostei: Cichlidae) from a reverse flowing river in the Peruvian Amazon, with a key to the species in the genus
Author
Říčan, Oldřich
197D8E32-925D-4A16-8ED1-9E13C74D98D6
University of South Bohemia, Faculty of Science, Department of Zoology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
oldrich.rican@prf.jcu.cz
Author
Říčanová, Štěpánka
9A90D79A-DBA7-4CF7-86C8-97FEE293F2AC
University of South Bohemia, Faculty of Science, Department of Zoology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
ricanova@prf.jcu.cz
text
European Journal of Taxonomy
2023
2023-06-01
870
167
201
http://dx.doi.org/10.5852/ejt.2023.870.2127
journal article
54259
10.5852/ejt.2023.870.2127
ff5f84b3-f279-4892-9622-7c28f6440af3
2118-9773
8006320
60245C9C-34EE-4F68-A346-F7A684E18EB6
Bujurquina omagua
sp. nov.
urn:lsid:zoobank.org:act:
8E478708-58F1-4E97-960C-9FCD93107C9A
Figs 6–10
;
Table 1
Bujurquina
sp.
Oran
Říčan
et al
. 2022
.
Bujurquina
sp.
Peru
1
Říčan
et al
. 2022
.
Diagnosis
Bujurquina omagua
sp. nov.
is highly apomorphic compared to other described species in the genus because it is unique in several character states. These include: 1) shape and pattern of the suborbital stripe in adults, which is bend and with a blotch at the postero-ventral end (vs straight or absent, with or without a blotch), with an ontogenetic change with juveniles and subadults having a straight stripe running diagonally postero-ventrally and starting from below the eye in juveniles (i.e., not bend as in adults) and without a blotch, 2) orange cheek and lower head coloration with alternating opalescent lines and series of spots on snout and spotted on cheek and lower head, 3) spinous portion of dorsal fin with a single thin diagonal black line per membrane, or two lines per membrane in
holotype
and largest adults (vs unpatterned in all Southern group species, or with circular blotches, with several thick diagonal black lines per membrane, or two thick horizontal bands across the dorsal fin in all other Northern group species), 4) longest snout of all species without overlap (mean 15.5%, 14.4–16.4% of SL; followed by
B. oenolaemus
with a mean of 11.4%, 10.3–13.1 of SL), and 5) most delicate LPJ, expressed by being shortest of all species with widest horns (length/width ratio 0.42–0.45 vs
0.50–0.64 in
all other species), one of the smallest dentigerous areas (length of dentigerous area/width of LPJ ratio 0.33–0.34 vs 0.34–0.44 except
B. tambopatae
,
B. moriorum
and
B. huallagae
where also 0.33–0.34), and the least robust dorso-ventrally (bone at posterior end of dentigerous area less thick or equal to length of largest posterior teeth vs much thicker than teeth in other species).
Bujurquina omagua
sp. nov.
is additionally diagnosed by the following unique combination of morphometric characters, the most pronounced of which characterize the robust head of the species: 1) second to third longest head (after
B. oenolaemus
and together with
B. labiosa
; both with a mean 37.0%, 36.3–38.0% of SL in
B. omagua
vs mean 39.1%, 38.6–40.4% of SL), 2) third longest preorbital distance (after
B. robusta
and
B. oenolaemus
; mean 9.3%, 8.5–10.0% of SL), 3) large interocular distance (largest mean value of all species, 12.5% of SL vs 9.7–12.4% however with large overlap of ranges with the other species), 4) rather wide head (mean 19.9%, range 19.1–20.7% of SL), 5) rather long preorbital distance (mean 9.3%, range 8.5–10.0% of SL, third longest based on mean value), 6) robust head which has rather small eyes (mean 11.3%, range 10.3–12.0% of SL), 7) very deep body (mean 45.1%, range 43.2–46.8% of SL, based on mean the second after
B. vitatta
), but 8) with rather long and shallow caudal peduncle (CPL mean 13.8%, range 12.6–15.6% of SL; CPD mean 16.6%, range 15.5–17.1% of SL), and 9) rather short last spine in the dorsal fin (mean 15.6%, range 12.3–17.1% of SL).
Etymology
The specific epithet ‘
omagua
’ is a noun in apposition given after the Omagua people, which were at the time of first contact with Europeans in the 16
th
century the dominant people along the banks of the Amazon River upstream from the mouth of the Negro River well into
Peru
.
Type material
Holotype
PERU
• adult
♂
,
97.4 mm
;
Amazonas river
basin,
Department Loreto
,
Maynas Province
,
District Las Amazonas
, close to Oran village,
Quebrada Sabalillo
, cabeceras upper locality P18-17;
3°
27´08.4˝
S
,
72°
29´11.8˝
W
;
97 m
a.s.l. based on GPS, 115 m a.s.l. based on Google Earth;
28 Jun. 2018
;
Říčan
leg.; clear-water stream with blackish tinge; ID tag 1189;
MUSM
70225
(
Figs 6
,
8–9
).
Paratypes
All from
Peru
,
Amazonas river basin
,
Department Loreto
,
Maynas Province
,
District Las Amazonas
, close to Oran village,
9 ex.
PERU
•
1 adult
,
78.6 mm
; same collection data as for holotype; ID tag 1188; GenBank:
OP436199
;
MUSM 70224
•
1 adult
,
98.9 mm
; same collection data as for holotype; ID tag 1190; GenBank:
OP436200
;
MUSM 70226
(
Figs 7–9
)
•
1 adult
,
69.7 mm
; same collection data as for holotype; ID tag 1191; GenBank:
OP436201
;
MUSM 70227
(
Fig. 7
)
•
1 adult
,
77.1 mm
; same collection data as for holotype; ID tag 1192; GenBank:
OP436202
;
MUSM 70228
(
Fig. 7
)
•
1 adult
,
78.7 mm
;
Amazonas river
basin,
Department Loreto
,
Maynas Province
, District Las Amazonas, close to
Oran village
, Qebrada Sabalillo on trail from mouth, P18-15;
3°
27´45.6˝
S
,
72°
29´22.5˝
W
;
90 m
a.s.l. based on GPS, 110 m a.s.l. based on Google Earth;
27 Jun. 2018
;
Říčan
leg.; clear-water stream with blackish tinge; ID tag 1182; GenBank: OP436196;
MUSM 70221
(
Figs 7
,
9
)
•
1 adult
,
79.9 mm
;
Amazonas river
basin,
Department Loreto
,
Maynas Province
, District Las Amazonas, close to
Oran village
, cabeceras of
Quebrada Sabalillo
, lower loc., P18-16;
3°
27´17.5˝
S
,
72°
29´22.8˝
W
;
75 m
a.s.l. based on GPS, 117 m a.s.l. based on Google Earth;
28 Jun. 2018
;
Říčan
leg.; clear-water stream with blackish tinge; ID tag 1185; GenBank: OP436197;
MUSM 70222
(
Figs 7
,
10
)
•
1 adult
,
92.6 mm
; same collection data as for preceding; ID tag 1186; GenBank:
OP436198
;
MUSM 70223
(
Fig. 7
)
•
1 adult
;
Amazonas river
basin,
Department Loreto
,
Maynas Province
, District Las Amazonas, close to
Oran village
, small unnamed quebrada just before entering
Oran creek
, P18-21;
3°
27´21.2˝
S
,
72°
30´43.2˝
W
;
82 m
a.s.l. based on GPS, 104 m a.s.l. based on Google Earth;
3 Jul. 2018
;
Říčan
leg.; clear-water stream with blackish tinge; ID tag 1200; GenBank: OP436204;
MUSM 70229
(
Fig. 7
)
•
1 juvenile
; same collection data as for preceding; GenBank:
OP436205
;
MUSM 70230
.
Description
Compound, based on
eight specimens
from Sabalillo creek,
69.7–98.9 mm
. Refer to
Figs 6–10
. Measurements summarized in
Table 1.
SHAPE
. Moderately elongate, rather robust, deep bodied (body depth mean 45.1%, range 43.2–46.8% of SL). Head especially robust, long (head length mean 37.0%, 36.3–38.0% of SL), wide (head width mean 19.9%, range 19.1–20.7% of SL), with large interocular distance (mean 12.5%, range 11.6–14.2% of SL). Frontal outline straight, nape and snout curved, anterior half of dorsal-fin base contour curved. Ventral outline curved. Snout long (mean 15.5%, 14.4–16.4% of SL). Preorbital distance long (mean 9.3%, range 8.5–10.0% of SL), preorbital bone much longer than high. Robust head with rather small eyes (mean 11.3%, range 10.3–12.0% of SL). Lips rather narrow, not turgid. Corner of mouth not reaching vertical from anterior margin of orbit, especially in largest specimens. Rather long and shallow caudal peduncle (CPL mean 13.8%, range 12.6–15.6% of SL; CPD mean 16.6%, range 15.5–17.1% of SL), and rather short last spine in dorsal fin (mean 15.6%, range 12.3–17.1% of SL).
SCALES
. Squ. long. (E1) scales 24 (5), 25 (3); 2 scales between L1 and dorsal fin anteriorly, 2 scales between L1 and L2. Upper lateral line (L1) with 15 (1), 16 (7) scales. Lower lateral line (L2) with 9 (4), 10 (3), 11 (1) scales; canal bearing scales on caudal fin: 0 in dorsal,
0-1 in
median and 0 in ventral sequence. Cheek scales in 3 (8) series. Anterior portion of caudal fin scaly.
FINS
. Dorsal fin XII.11 (1), XIII.10 (1), XIII.11 (1), XIV.9 (1), XIV.10 (4). Soft anal fin pointed, 3
rd
ray longest, reaching to middle of caudal fin or slightly beyond. Anal fin III.8 (8). Pectoral fin with rounded tip, reaching to above genital papilla to anal-fin origin (to 2
nd
spine in
one specimen
); Pectoral fin 13 (8). Pelvic fin pointed, first ray slightly produced, reaching to origin of anal fin or base of 1
st
spine of anal fin. Caudal fin rounded, without well-developed streamers or with only short streamers.
GILL-RAKERS
. 1 epibranchial,
1 in
angle, and 5 (3), 6 (4), 7 (1) ceratobranchial rakers externally on first arch.
JAW
TEETH
. An outer series of stronger, conical, sharply pointed, slightly recurved teeth, slightly increasing in size anteriorly, not worn,
15–22 in
outer hemiseries in upper jaw.
LOWER
PHARYNGEAL
JAW
AND
TEETH
. Lower pharyngeal jaw (LPJ) as examined in
two specimens
(
79.8– 98.9 mm
) (
Fig. 10
) very delicate, most delicate LPJ of all described species of
Bujurquina
, very shallow vertically dorso-ventrally (bone at posterior end of dentigerous area less thick than length of largest posterior teeth in the smaller specimen, almost so in the larger specimen vs thicker than the teeth in all other species). LPJ also shortest and widest of all species, length/width ratio 0.42–0.45 (vs
0.50–0.64 in
all other species). LPJ tooth-plate (due to the longest arms within
Bujurquina
) also one of the shortest in genus, length of dentigerous area/width of LPJ ratio 0.33–0.34 (vs 0.34–0.44 except
B. tambopatae
,
B. moriorum
and
B. huallagae
where also 0.33–0.34), Teeth slightly laterally compressed (most pronounced in posterior row), slightly bicuspid with main cusp posterior, central and posterior teeth largest, smaller towards outside, central teeth with flat-worn apex, others with pronounced tip.
Coloration in alcohol
Coloration limited to melanin patterns in preserved state, ground colour light yellowish-brownish, lighter towards whitish on chest and anterior abdomen, dusky greyish on anterior head, snout, and dorsum. Dark diffuse and wide interorbital band. Operculum silvery greyish.
Fig. 6.
Bujurquina omagua
sp. nov.
, holotype (MUSM 70225), 97.4 mm, ID tag 1189, Quebrada Sabalillo, cabeceras upper loc. P18-17 (3°
27´08.4˝
S, 72°
29´11.8˝
W).
A
. Left side.
B
. Right side reversed.
Table 1.
Proportional measurements in percent of standard length of nine specimens of
Bujurquina omagua
sp. nov.
larger than 60 mm SL. Abbreviation: SD = standard deviation.
|
B. omagua
sp. nov.
|
| Holotype |
Mean |
Range |
SD |
n |
| min |
max |
| Standard length (mm) |
97.4 |
84.1 |
69.7 |
98.9 |
8 |
| Head length |
36.3 |
37.0 |
36.3 |
38.0 |
0.69 |
8 |
| Snout length |
16.3 |
15.5 |
14.5 |
16.4 |
0.84 |
8 |
| Body depth |
43.2 |
45.1 |
43.2 |
46.8 |
1.00 |
8 |
| Orbital diameter |
10.3 |
11.3 |
10.3 |
12.0 |
0.66 |
8 |
| Head width |
19.7 |
19.9 |
19.1 |
20.7 |
0.64 |
8 |
| Interorbital width |
12.6 |
12.5 |
11.6 |
14.2 |
0.90 |
8 |
| Preorbital depth |
9.6 |
9.3 |
8.5 |
10.0 |
0.54 |
8 |
| Caudal-peduncle depth |
15.5 |
16.6 |
15.5 |
17.1 |
0.52 |
8 |
| Caudal-peduncle length |
12.7 |
13.8 |
12.6 |
15.6 |
1.05 |
8 |
| Pectoral-fin length |
33.3 |
33.4 |
32.4 |
34.8 |
0.81 |
8 |
| Pelvic-fin length |
36.0 |
35.9 |
30.1 |
39.5 |
2.92 |
8 |
| Last dorsal-fin spine length |
15.7 |
15.6 |
12.3 |
17.1 |
1.59 |
8 |
Up to four clearly defined grey lines between eye and mouth corner and on anterioir cheek interspersed with spots, rest of cheek as well as opercular series richly spotted. Suborbital stripe rather marrow and of uniform width, diffuse and ghost-like, bend from behind eye forward to cheek and then postero-ventrally to a variously developed suborbital stripe blotch in adults (never ocellated and with diffuse borders). In one collected juvenile specimen and in subadults straight (i.e., not bend), running from below eye (vs from behind eye) diagonally postero-ventrally.
Midlateral band continuous from head to penultimate vertical bar on body, strongly pigmented and black, very wide anteriorly and gradually narrowing posteriorly. No interruption in vertical bar 5 (sensu
Říčan
et al.
2005
), midlateral blotch (usually present and dominant in bar
5 in
cichlasomatine cichlids) is absent. Lateral band continued on head across nape close behind eye.
Body with five vertical bars plus one caudal peduncle bar and a caudal peduncle blotch (usually vertically elongated). The five body bars correspond to ontogenetic bars 2–5 with the anteriormost ontogenetic bars 6–7 fused into one wide bar below midlateral band but visible as two above it. Posterior body bars (2–4) narrow and tightly spaced, anterior bars (5, 6+ 7) wide and widely spaced. Bars darkest dorsally, reaching ventrally approximately to level of lower edge of caudal peduncle. Bars do not extend onto dorsal fin.
Body scale centres (below midlateral band) with dark blotches, more pronounced in zones of vertical bars.
Dorsal fin light grey, lappets indistinct, with a single narrow grey diagonal stripe per membrane in spinous part, with blotches on ventral portion of soft part. Anal fin light grey, with spots on last about four membranes. Caudal fin light grey with minute slightly elongate dark dots on anterior half, distally membranes hyaline with grey edges. Pelvic fin light grey, edge and produced portion of first ray white.
Fig. 7.
Bujurquina omagua
sp. nov.
, paratypes.
A
. MUSM 70223, P18-16_1186, 92.6 mm.
B
. MUSM 70222, P18-16_1185, 79.9 mm.
C
. MUSM 70221, P18-15_1182, 78.7 mm.
D
. MUSM 70226, P18- 17_1190, 98.9 mm.
E
. MUSM 70229, P18-21_1200.
F
. MUSM 70227, P18-17_1191, 69.7 mm.
G
. MUSM 70228, P18-17_1192, 77.1 mm.
Coloration in life
Melanin patterns as in preserved. Lower head, cheek, and opercular series yellow-orange, with opalescent golden to azure blue lines and spots, arranged as up to four clearly defined lines between eye and mouth corner and on anterioir cheek interspersed with spots, rest of cheek as well as opercular series richly spotted. Fins orange, pelvic fin yellow, edge and produced portion of first ray white (opalescent). Spinous portion of dorsal fin with a single thin diagonal black line per membrane in juveniles and subadults, and with two lines per membrane in
holotype
and large adults. Lower lip pale greyish to indistinctly light azure blue. Midlateral blotch present only as a paler reflective area within the dark midlateral band (hence absent from coloration of preserved specimens).
Fig. 8.
Bujurquina omagua
sp. nov.
, color photos of preserved specimens.
A
. Holotype (MUSM 70225, ID tag 1189), 97.4 mm.
B
. Paratype (MUSM 70226, P18-17_1190), 98.9 mm.
Fig. 9.
Bujurquina omagua
sp. nov.
, black and white photos of preserved specimens.
A
. Holotype (MUSM 70225, ID tag 1189), 97.4 mm.
B
. Paratype (MUSM 70226, P18-17_1190), 98.9 mm.
C
. Paratype (MUSM 70221, P18-15_1182), 78.7 mm.
Habitat
Bujurquina omagua
sp. nov.
was found only in small rainforest streams within the basins of the Sabalillo and
Oran
creeks. The localities (
Fig. 11
) were around
2 m
wide streams, with shallow water (less than
1 m
except in deeper pools) but deep mud and accumulated debris, blackish water, and only weak or moderate current.
Bujurquina omagua
has not been collected from the main streams of the
Oran
creek or from the lower sections of the
Oran
and Sabalillo creeks (
Fig. 12
), which have muddy water and where
B. syspilus
was found.
Distribution
Bujurquina omagua
sp. nov.
is only known from the Sabalillo and
Oran
creeks which empty into the Amazon River on either side of the village of
Oran
located on the first high ground just downstream from the mouth of the Napo into the Amazon, District Las Amazonas, Maynas Province, Department
Loreto
,
Perú
(
Figs 1
,
13
).
Morphometric differentiation of
Bujurquina omagua
sp. nov.
Bujurquina omagua
sp. nov.
has a highly apomorphic head and body shape that sets it apart from the sympatric/parapatric species. When analyzed through PCA these species are arranged along the main tentic-lotic axis as corresponding to their lowland-upland habitats (
Figs 14–15
). The lotic/lentic ecomorphology dichotomy is in the PCA analyses best correlated with caudal peduncle length (long vs short), caudal peduncle depth (narrow vs deep), body depth (narrow vs deep), the size of the eye (orbital diameter; small vs large), pectoral fin length (short vs long), and last dorsal fin spine length (short vs long).
Fig. 10.
Bujurquina omagua
sp. nov.
, paratype (MUSM 70222, P18-16_1185, 79.9 mm), lower pharyngeal tooth plate in occlusal view. Scale bar = 1 mm.
Fig. 11.
Type localities of
Bujurquina omagua
sp. nov.
A–B
. P18-15, Qebrada Sabalillo on trail from mouth, (3°
27´45.6˝
S, 72°
29´22.5˝
W), 27
th
June 2018.
C
. P18-16, cabeceras of Quebrada Sabalillo, lower loc. (3°
27´17.5˝
S, 72°
29´22.8˝
W), 28
th
June 2018.
D
. P18-17, holotype locality, cabeceras of Quebrada Sabalillo, upper loc. (3°
27´08.4˝
S, 72°
29´11.8˝
W), 28
th
June 2018.
E
. P18-21, small unnamed quebrada just before entering Oran creek, (3°
27´21.2˝
S, 72°
30´43.2˝
W), 3
rd
July 2018.
The remaining characters are not correlated with the main ecomorphological dichotomy (i.e., interocular distance, head width, head length, preorbital distance, snout length, and first ventral fin ray length) (
Figs 14–15
).
The lotic/lentic ecomorphology dichotomy is best visible in the analysis including all central western Amazonian species (
Figs 1
and
14
), while the diagnostic characters of
Bujurquina omagua
sp. nov.
are best visible in the analysis excluding the westernmost and most highland species
B. zamorensis
(
Fig. 15
).
Bujurquina omagua
is in the PCAs distinguished from the sympatric/parapatric species predominantly by characters not correlated with the lotic-lentic, namely large head, wide head, long snout, and long preorbital dostance. All these diagnostic characters are in line with the diagnosis of the species based on means and ranges of the morphometric characters (see above).
Bujurquina omagua
sp. nov.
has an outlying LPJ shape that can be described as the most delicate LPJ found among the valid species of
Bujurquina
(
Fig. 16
). The LPJ of
Bujurquina omagua
(studied in
two specimens
, see above) as expressed by proportional measurements is the shortest and widest of all species (L/W ratio) and the LPJ tooth-plate is the shortest in the genus (Ld/W ratio). Additionaly to this the LPJ is very shallow vertically dorso-ventrally, but this character was scored as binary, in comparison to the length of teeth (see Results), and thus not included in the PCA analysis.
Paradoxically, the most delicate LPJ of
B. omagua
sp. nov.
is associated with one of the largest heads among species of
Bujurquina
(together with
B. labiosa
) and with the longest snout among species of
Bujurquina
. A similar head and snout shape in
B. oenolaemus
is however associated with the most robust LPJ (
Fig. 16
) of this molluscivorous species.
Fig. 12.
Lower portions of Sabalillo and Oran streams with muddy water with a blackish tinge (June 2018).
Bujurquina omagua
sp. nov.
was not encountered in these habitats, which are typical for
B. syspilus
(Cope, 1872)
in this area (see Fig. 13).
A
. Quebrada Sabalillo close to mouth into Amazon River.
B
. Oran creek at mouth of P18-21.
A similar combination of a long snout and large head with a very delicate LPJ as in
B. omagua
sp. nov.
is however also known from the cichlid genus
Australoheros
Říčan & Kullander,
2006
in the species
A. forquilha
Říčan & Kullander, 2008
and
A. ykeregua
Říčan, Piáleck, Almirón & Casciotta, 2011
(
Říčan & Kullander 2008
;
Říčan
et al.
2011
).
Fig. 13.
Distribution of
Bujurquina omagua
sp. nov.
and parapatric species in the so far whole known area close to Oran village, District Las Amazonas, Maynas Province, Department Loreto, Perú.
Fig. 14.
Morphometric variation and discrimination of Northern group species in
Bujurquina
Kullander, 1986
from the western Amazon river basin based on morphometric proportional values of SL in PCA based on specimens ≥ 60 mm SL. Colors represent individual species. Note main separation along PC1 which also corresponds to two main ecomorphs (lotic and lentic). Note that
B. omagua
sp. nov.
is separated from these geographically closest species by its large head. Note that
B. zamorensis
(Regan, 1905)
is the most lotic and
B. syspilus
(Cope, 1872)
the most lentic species identified by the analysis.
Fig. 15.
Morphometric variation and discrimination of Northern group species in
Bujurquina
from the central western Amazon river basin (i.e., excluding
B. zamorensis
(Regan, 1905))
based on morphometric proportional values of SL in PCA based on specimens ≥ 60 mm SL. Colors represent individual species. Note main separation along PC1 which also corresponds to two main ecomorphs (lotic and lentic). Note that
B. omagua
sp. nov.
is separated from these geographically closest species by its large head and long snout. Note improved separation of
B. huallagae
Kullander, 1986
,
B. ortegai
Kullander, 1986
and
B. moriorum
Kullander, 1986
after exclusion of
B. zamorensis
(cf. Fig. 14).
Fig. 16.
PCA based on morphometric proportional values of LPJ of all described species in
Bujurquina
Kullander, 1986
based on specimens ≥60 mm SL. Colors represent individual species. Note that
B. omagua
sp. nov.
has the most outlying LPJ shape.
Phylogeny of
Bujurquina
and phylogenetic position of
Bujurquina omagua
sp. nov.
Phylogenetic analyses of the 1055 characters
cytb
data matrix performed with MP in PAUP* (including all ingroup sequences) and BI analyses in MrBayes and BEAST (performed with the corresponding haplotypes data matrix) provided robust and very similar results. BI runs in independent analyses with the best-fitting model of evolution (GTR+I+G) converged well (ESS>200 for all parameters; burn-in 10%) and led to identical topologies under the same settings. The NJ and MP analyses were done with the complete dataset, the BI and BEAST analyses with the haplotype dataset. No phylogenetic differences were found between the MP, BI and BEAST analyses, and hence only the BEAST analysis is shown in
Fig. 17
.
The phylogenetic reconstructions divide
Bujurquina
into two main clades that can be diagnosed by patterned vs unpatterned dorsal fin, corresponding in geographical terms to Northern vs Southern group (
Figs 1
and
17
). The main biogeographic dichotomy within the genus between the Southern and Northern groups is within the present upper
Ucayali
basin in
Peru
(
Fig. 1
).
The two main clades of
Bujurquina
are dated as having diverged at 16.6 Ma. Within the Southern group the two southern-most species from
Argentina
,
Paraguay
,
Brazil
and
Bolivia
are sister species (
B. vittata
and
B. oenolaemus
), and they are a sister group to the clade composed of the Peruvian
B. eurhinus
and
B. tambopatae
as sister species, followed by the Bolivian
B
. sp.
Bolivia
and then the Peruvian
B. robusta
. The phylogenetically basal-most species of the Southern group is the Peruvian
B. labiosa
. The Peruvian species are thus in basal positions within the Southern group, and they also have the longest internodes and the earliest dates of divergence based on molecular clock dating, with the time frame of divergence among the Peruvian species dated between 12.4 Ma and 3.0 Ma (
Fig. 17
).
Fig. 17.
Phylogenetic relationships and species delimitation within
Bujurquina
Kullander, 1986
based on the cytb marker from BEAST analysis. Numbers at nodes show age in Ma, grey bars at nodes show confidence intervals of age estimates (95% HPD). Bayesian posterior probabilities above 0.95 are shown as black points on nodes. Scale bar shows 5 My. Note the two main groups of
Bujurquina
.
The Northern group of
Bujurquina
is made up of two highly divergent clades (
Fig. 17
) unlike the situation in the Southern group. The first clade within the Northern group shows a younger basal divergence at 3.9 Ma and includes, as a basal species, the here described
B. omagua
sp. nov.
, and then, among the Peruvian species,
B. huallagae
and
B. syspilus
. Samples of the morphologically and biogeographically Southern group species
B. megalospilus
are found within
B. syspilus
together with some samples of the Southern group species
B. labiosa
and
B. robusta
(Supp. file 2:
Fig. S3
). These three species clearly are Southern group species whose mtDNA in these particular samples was swept by mtDNA from
B. syspilus
following a single postulated hybridization event from
B. syspilus
into the three introgressed species, dated in our phylogeny at 0.2 Ma (cf.
Fig. 17
and Supp. file 2:
Fig. S3
). Non-introgressed samples of
B. labiosa
and
B. robusta
are found as separate Southern group species in all phylogenetic analyses (see
Fig. 17
). Non-introgressed samples of
B. megalospilus
have not been found in this study. The close phylogenetic position in mtDNA of the morphologically dissimilar yet clearly Northern group species
B. syspilus
and
B. huallagae
may potentially also be a case of
B. syspilus
introgression into the sampled specimen of
B. huallagae
. This specimen was sampled in the lowermost portion of its distribution closest to the natural distribution of
B. syspilus
and not from the
type
locality of
B. huallagae
much higher up the namesake river.
In our present taxon sampling the first clade within the Northern group thus has a 10 my time gap from the basal node at 13.9 Ma to the presently sampled divergence at 3.9 Ma and this may suggest the existence of yet undiscovered older diverged species in this clade, or alternatively, it suggests extinction within the clade.
The second clade within the Northern group shows a younger basal divergence at 7.9 Ma, hence also with a time gap and with similar potential implications, which is strenghtened by the isolated position of the basal-most species of this clade,
B. mariae
(
Fig. 17
).
Bujurquina mariae
(from
Colombia
) is the only species so far sampled from the Orinoco basin to the north of the Amazon basin. The two remaining Peruvian species (
B. peregrinabunda
and
B. moriorum
) diverged at 4.6 Ma, but they are not found as closely related in the mtDNA phylogeny despite being more similar and lowland parapatric species. Instead, the lowland
B. peregrinabunda
is found closely related to the allopatric Andean endemic
B. zamorensis
from
Ecuador
plus one putative lowland Ecuadorian species, most likely also found in
Peru
(
B
. sp.
Ecuador
13).
Bujurquina moriorum
is found in a clade with two other putative Peruvian species from the Marañón basin.
Phylogeny and coloration patterns: the two main groups and phylogenetic lineages of
Bujurquina
Our phylogenetic results have shown that
Bujurquina
is divided into two main clades. One clade, based on distribution patterns referred to us as the Northern group, is characterized by ornamented dorsal fins and a midlateral stripe running generally to the dorsal margin of the caudal peduncle (
Figs 1
,
4–5
and
17
). In contrast to this the Southern group is characterized by unpatterned (hyaline, i.e., without any markings) dorsal fins and a midlateral stripe that always runs towards the posterior insertion of the dorsal fin (
Figs 1–3
and
17
). Lower lip coloration is another character that almost fully separates the two groups, since in majority of the Northern group species the lower lip is distinctly azure blue while in the Southern group species it is always the same color as the upper lip (i.e., never blue).
Key to the species of
Bujurquina
For the key we have chosen to use only readily visible external characters. All characters except where specifically noted are for large adult specimens (usually above
60 mm
SL), especially the color and coloration pattern characters, where most are best visible in live specimens. In bold are the main distinguishing character states for each step.
1. Spinous portion of the dorsal fin ornamented (i.e., with blotches, lines etc.); midlateral stripe on body oriented towards posterior insertion of dorsal fin except in one species (
B. syspilus
), i.e., oriented nearly horizontally; flanks with dark, squarish or wedge-shaped spots, in overlapping region between scale base and overlying scale margin except in two species (
B. mariae
and
B. ortegai
) ................ 2
– Spinous portion of the dorsal fin
unpatterned
(i.e., hyaline without any markings); midlateral stripe on body oriented
towards soft portion
of dorsal fin, i.e., oriented more dorsally, flanks without spots .................................................................................................................................................. 9
2. Spinous portion of the dorsal fin with
diagonal lines
(i.e., dark lines on a hyaline background) ... 3
– Spinous portion of the dorsal fin with
circular markings
(i.e., hyaline blotches on a dark background) ...................................................................................................................................... 6
3. Diagonal lines on spinous portion of the dorsal fin
thick
, sometimes barely recognisable as diagonal line but approaching blotches in shape, arranged as one longitudinal series with one line per membrane, dorsal-fin lappets orange; midlateral stripe on body oriented
towards soft portion
of dorsal fin; suborbital stripe vertical, in adults barely visible .......................
B. syspilus
(Cope, 1872)
– Diagonal lines on spinous portion of the dorsal fin
thin
.................................................................. 4
4.
Three
diagonal lines vertically on each membrane of spinous portion of the dorsal fin, each line spanning three consecutive membranes, lines oriented distinctly diagonal, about 45%, dorsal-fin lappets orange; suborbital stripe vertical, in adults distinct.................
B. mariae
(Eigenmann, 1923)
–
One to two
diagonal lines per membrane on spinous portion of the dorsal fin ............................... 5
5. Lines per membrane oriented
only slightly diagonal
, two lines only in largest adult specimens, one line in dorsal portion of membrane in all other sizes, dorsal-fin lappets dark, with orange tip; suborbital stripe bent from vertical to posteriad in juveniles, reduced to a preopercular spot in adults; large head, length equal or above 36.3% SL; longest snout of all species without overlap (mean 15.5%, 14.4–16.4% of SL) ..................................................................................
B. omagua
sp. nov.
– Lines per membrane oriented
distinctly diagonal
, about 45%, dorsal-fin lappets nearly hyaline, only very slightly tinged orange; suborbital stripe slightly bent from vertical to posteriad, in adults well developed .........................................................................................
B. ortegai
Kullander, 1986
6. Suborbital stripe
vertical
.................................................................................................................. 7
– Suborbital stripe
bent
from vertical to posteriad .............................................................................. 8
– Suborbital stripe
inclined
posteriad, in adults reduced to its ventral portion in the form of a short stripe or a preopercular spot; dorsal-fin lappets dark to black, not orange ......................................... .............................................................................................................
B. moriorum
Kullander, 1986
7. Suborbital stripe
vertical
,
shifted posteriorly
to a position behind the eye, in adults always as a stripe, sometimes reduced only to its ventral portion; dorsal-fin lappets orange-brown, same color as rest of markings on dorsal fin, not orange .................................
B. peregrinabunda
Kullander, 1986
– Suborbital stripe
vertical
, in adults
whole
; dorsal-fin lappets orange-brown, same color as rest of markings on dorsal fin, not orange .....................................................
B. huallagae
Kullander, 1986
8. Suborbital stripe
bent
from vertical to posteriad, in adults
reduced to an ocellated preopercular spot
; dorsal-fin lappets orange-brown, same color as rest of markings on dorsal fin, not orange ..... ..............................................................................................................
B. zamorensis
(Regan, 1905)
– Suborbital stripe
bent
from vertical to posteriad, in adults
whole
; dorsal-fin lappets
white
with dark base ...................................................
B. pardus
Arbour, Barriga Salazar & López-Fernández, 2014
9. Head
large
, length equal or above 37% SL .................................................................................... 10
– Head
small
, mean length below 35.5% SL ......................................................................................11
10. Mean length of head above 38.6% of SL, average 39.1%, lower pharyngeal teeth molariform, suborbital stripe in adults complete, dorsal-fin lappets white with dark base .................................... ..........................................................................................................
B. oenolaemus
Kullander, 1987
– Mean length of head above 37%, lips hypertrophied, suborbital stripe in adults incomplete, limited to below eye or to middle of cheek (does not reach angle of preopercle), dorsal-fin lappets white with dark base ..................................................................................................
B. labiosa
Kullander, 1986
11. Suborbital stripe in adults
complete
............................................................................................... 12
– Suborbital stripe in adults
incomplete
........................................................................................... 13
– Suborbital stripe in adults
reduced
to preopercular spot ............................................................... 14
– Suborbital stripe in adults
absent
, dorsal-fin lappets
white
with dark base ....................................... ...............................................................................................................
B. eurhinus
Kullander, 1986
12. Suborbital stripe in adults
complete
,
distinct
, dorsal-fin lappets dark red to brown ......................... ......................................................................................................................
B. vittata
(Heckel, 1840)
– Suborbital stripe in adults
complete
,
indistinct
, dorsal-fin lappets distinctly
orange
...................... ..................................................................................................................
B. robusta
Kullander, 1986
– Suborbital stripe
complete
,
indistinct
, dorsal-fin lappets
white
......
B. cordemadi
Kullander, 1986
13. Suborbital stripe in adults
incomplete, limited to below eye
, weakly developed, dorsal-fin lappets
red
in anterior portion,
black
in posterior portion
........................
B. megalospilus
Kullander, 1986
– Suborbital stripe in adults
incomplete, limited to below eye
, weakly developed, dorsal-fin lappets
white
.................................................................................................
B. tambopatae
Kullander, 1986
14. Suborbital stripe in adults
reduced
to preopercular spot,
well developed
, in most specimens clearly visible, dorsal-fin lappets with
dark
tips ................................................
B. hophrys
Kullander, 1986
– Suborbital stripe in adults
reduced
to preopercular spot,
very weakly developed
, in most specimens almost invisible, dorsal-fin lappets with
dark orange
tips .............
B. apoparuana
Kullander, 1986