Content uploaded by Jay Richard Stauffer
Author content
All content in this area was uploaded by Jay Richard Stauffer on May 12, 2020
Content may be subject to copyright.
Cuaderno N° 12
Colección Naturaleza
Cuaderno N° 12
Colección Naturaleza
El Complejo de Especies de la Mojarra Común en DosEl Complejo de Especies de la Mojarra Común en Dos
El Complejo de Especies de la Mojarra Común en DosEl Complejo de Especies de la Mojarra Común en Dos
El Complejo de Especies de la Mojarra Común en Dos
Lagunas Cratéricas NicaragüensesLagunas Cratéricas Nicaragüenses
Lagunas Cratéricas NicaragüensesLagunas Cratéricas Nicaragüenses
Lagunas Cratéricas Nicaragüenses
The Midas Cichlid Species Complex in TwoThe Midas Cichlid Species Complex in Two
The Midas Cichlid Species Complex in TwoThe Midas Cichlid Species Complex in Two
The Midas Cichlid Species Complex in Two
Nicaraguan Crater LakesNicaraguan Crater Lakes
Nicaraguan Crater LakesNicaraguan Crater Lakes
Nicaraguan Crater Lakes
El Complejo de Especies de la Mojarra Común en DosEl Complejo de Especies de la Mojarra Común en Dos
El Complejo de Especies de la Mojarra Común en DosEl Complejo de Especies de la Mojarra Común en Dos
El Complejo de Especies de la Mojarra Común en Dos
Lagunas Cratéricas NicaragüensesLagunas Cratéricas Nicaragüenses
Lagunas Cratéricas NicaragüensesLagunas Cratéricas Nicaragüenses
Lagunas Cratéricas Nicaragüenses
The Midas Cichlid Species Complex in TwoThe Midas Cichlid Species Complex in Two
The Midas Cichlid Species Complex in TwoThe Midas Cichlid Species Complex in Two
The Midas Cichlid Species Complex in Two
Nicaraguan Crater LakesNicaraguan Crater Lakes
Nicaraguan Crater LakesNicaraguan Crater Lakes
Nicaraguan Crater Lakes
Cuadernos de Investigación de la
UCA / N° 12
1
Descriptions of Three New Species of Cichlid Fishes
(Teleostei: Cichlidae) from Lake Xiloá, Nicaragua
Jay R. Stauffer, Jr.1 and K. R. McKaye2
1School of Forest Resources, The Pennsylvania State University,
University Park, PA 16802 U.S.A.
2Appalachian Laboratory, UMCES, 301 Braddock Rd, Frostburg,
MD 21532 U.S.A
Abstract
Three new species in the Amphilophus citrinellus
(Günther) species complex from Lake Xiloá are de-
scribed. Historically, many forms have been recorded
that are phenotypically similar to A. citrinellus and in
the crater lakes of Nicaragua this complex was previ-
ously considered to be represented by a single, very
variable species. In Lake Xiloá, the three new species
mate assortatively, and differ morphologically from
each other and from all other described species in the
A. citrinellus complex.
Introduction
Cichlid nomenclature in Central America is in a state
of controversy. Kullander and Hartel (1997) recently
discussed the systematic status of the genera Amphi-
lophus, Baiodon, Hypsophrys, and Parachromis. They con-
cluded that the name Amphilophus is still available as a
generic name, but discussed the confusion surround-
ing Amphilophus froebelii, the type species of Amphi-
lophus. Essentially, Barlow and Munsey (1976) proposed
that the junior synonym of this form, Amphilophus
labiatus (Günther), should be maintained, since no type
material can be found for A. froebelii. If the description
of A. froebelii is adequate, but the type material has been
lost, then a neotype can be designated. Kullander and
Hartel (1997) suggested that since A. froebelii is known
from Lake Nicaragua and A. labiatus was described
from Lake Managua, both names should be maintained
since the two lake populations may be heterospecific.
If, in fact, these two species are conspecific, article
23.9.1.2 of the ICZN states that a junior synonym may
be used as the valid name if “the senior synonym or
homonym has not been used as a valid name after 1899”
and if “the junior synonym or homonym has been used
for a particular taxon, as its presumed valid name, in
at least 25 works, published by at least 10 authors in
the immediately preceding 50 years and encompass-
ing a span of not less than 10 years.”
Jordan et al. (1930) referenced Amphilophus froebelii,
and stated that Amphilophus Agassiz has priority over
Astatheros Pellegrin. Miller (1966) placed the Astatheros
longimanus (Günther) group in Amphilophus. Currently,
Astatheros and Amphilophus are regarded as two differ-
ent genera. The type species of Astatheros, Astatheros
macracanthus (Günther), was previously regarded as an
Amphilophus citrinellus (Günther) type cichlid, but Roe
et al. (1997) placed this species genetically closer to the
substrate sifters, Astatheros alfari/longimanus. Konings
(pers. comm.) has observed A. macracanthus in the wild
and notes that their behavior and habitat preference
resembles more that of longimanus than citrinellus).
Since Amphilophus froebelii has been used since 1899
the validation of the junior synonym, i.e. A. labiatus for
A. froebelii, must be based on the approval of the Inter-
national Commission on Zoological Nomenclature.
Irrespective of the nomenclatural problems, the ge-
nus Amphilophus is at best vaguely diagnosed (Bussing
and Martin 1975, Kullander and Hartel 1997). Regan
(1906-1908) gave several characters of the genus, in-
cluding: produced snout, maxillary not extending be-
yond the anterior margin of the eye, long pectoral fins,
and presence of 5-9 vertical bars laterally. He did not,
however, provide any diagnosis of the genus or specu-
late on putative synapomorphies.
The confusion surrounding the cichlid nomenclature
is further exacerbated when examining Amphilophus
citrinellus (Günther) and phenotypically similar forms
(Gill and Bransford 1877, Günther 1869, Stiassny 1991,
Kullander and Hartel 1997, Roe et al. 1997). Meek (1907),
one of the pioneers to work in Nicaragua, considered
A. citrinellus by far the most variable species and rec-
ognized several forms:
“Of all the species (of) fishes in these lakes, this one is by
far the most variable. I made many repeated efforts to divide
this material. . . from two to a half-dozen or more species,
but in all cases I was unable to find any tangible constant
characters to define them. To regard them as more than one
species meant only to limit the number by the material at
hand and so I have lumped them all in one.”
Cuadernos de Investigación de la U.C.A.
12:1-18 (1 Julio 2002)
Cuadernos de Investigación de la
UCA / N° 12
2
Fig 1. Map of the Pacific region of Nicaragua showing the localities discussed in the text.
Subsequently, Barlow and Munsey (1976) recognized
three different species within the A. citrinellus complex:
A. citrinellus, A. labiatus, and Amphilophus zaliosus
Barlow. McKaye (1980) concluded that since the mor-
phs of the Midas Cichlid mated assortatively and se-
lected different habitats in which to breed, sympatric
speciation of this complex would be possible. In other
words, new species could quickly evolve in each of the
isolated crater lakes (Stauffer et al. 1995, Murry et al.
2001, Vivas and McKaye 2001). Nevertheless, through
the 80s the prevailing scientific view was that there were
two polymorphic species, the Red Devil Cichlid, A.
labiatus, and the Midas Cichlid, A. citrinellus. The spe-
cific status of the Arrow Cichlid, A. zaliosus, was seri-
ously questioned. Villa (1982), for example, stated that
it should be considered “a labiatum with ‘normal’ lips.”
In the 1990s, we organized several expeditions and
examined the distribution of fishes in eight Nicaraguan
crater lakes (Waid et al. 1999), and discovered great
morphological variability in this species complex. De-
tailed behavioral studies using SCUBA in the crater
lakes Xiloá and Apoyo (Fig. 1-3) demonstrated that
several different forms (but none based on the gold/
normal color distinction — Barlow 1976, McKaye
and Barlow 1976) were 100% mating assortatively.
Our subsequent behavioral and genetic work con-
firmed that Barlow was correct in determining that
the Arrow Cichlid is a valid species (McKaye et al.
1998).
Given the great variability in both color and mor-
phology, we have been cautious in assigning specific
status to the many newly discovered forms. Instead
we have referred to various taxa as Evolutionary Sig-
nificant Units (ESU) (Stauffer et al. 1995). We are now
ready to describe three new species in the A. citrinellus
species complex from Lake Xiloá.
Chiltepe Peninsula
Lake
Managua
Xiloá
Apoyo Lake
Nicaragua
Managua
Cuadernos de Investigación de la
UCA / N° 12
3
Fig 2. View from the eastern shore of Lake Xiloá (photo by Ad Konings).
Fig 3. A composite aerial view of Lake Apoyo (photo by Ad Konings).
Cuadernos de Investigación de la
UCA / N° 12
4
Lake Xiloá, is located at the center of the volcanic
chain of the Pacific Region of Nicaragua, in the Chiltepe
peninsula (Fig. 1). This peninsula is an approximately
circular protrusion into Lake Managua. Also located
in this peninsula is Lake Apoyeque. The area of Lake
Xiloá is 3.75 km2, and its mean depth and maximum
depth are 60 m and 88.5 m, respectively (BANIC, 1977,
Wa id et al. 1999). Lake Xiloá originated by a collapse
on the southeastern edge of a volcano around 10,000
years ago (BANIC, 1977). As a result of the way it col-
lapsed, it has two drastically different bottom profiles.
At its southeastern end, a low rim rises just above its
surface. The bottom profile is a gentle slope, and the
bottom consists mostly of silt and sand (McKaye 1984).
This end is separated from Lake Managua by 1 km of
rather flat terrain. Lake Xiloá was formerly connected
to Lake Managua (Villa 1968). At the opposite end (the
one closest to Lake Apoyeque) the rim rises to 220 m
above the lake surface and the bottom consists of large
jumbled boulders and rocky formations descending
rapidly to the depths (McKaye 1984). Located at its
northern end are sulfurous springs, and the water tem-
perature may reach 37oC in this part of the lake (BANIC,
1977)
Typical of these crater lakes, its waters are alkaline
(pH=7.9, hard (443 ppm as CaCO3), and as the second
most saline of the crater lakes (conductivity=5,580 µS
Waid et al. 1999) Lake Xiloá is a relatively oligotrophic
lake. Because of the very low southeastern rim Lake
Xiloá is the least wind-protected of the crater lakes, and
therefore its waters are very well mixed (Barlow et al.,
1976), resulting in significant amounts of dissolved
oxygen at great depths (BANIC, 1977).
Methods and Materials
Type specimens were borrowed from several muse-
ums (Table 1). Fishes were collected in Lake Xiloá by a
diver with SCUBA and a monofilament gill net. Color
notes were made on live fish or recently preserved
specimens. Specimens were fixed in 10% formalin with
their fins pinned and preserved in 70% ethanol.
All measurements were made with dial calipers that
were interfaced directly with a computer. External
counts and measurements followed Barel et al. (1977)
and Stauffer (1991), except that head depth was taken
along the vertical through the posterior edge of the
midpoint of the branchiostegal. The number of scales
in the lateral-line series exclude scales in the overlap-
ping portion of the lower and upper lateral lines; pored
scales located posterior to the hypural plate were re-
corded separately. Except for gill-raker meristics, we
made all counts and measurements on the left side of
the fish. Morphometric values are expressed as percent
standard length (SL) or percent head length (HL).
Historically, morphological differences were delim-
ited by meristic and univariate morphometric analysis
and many cichlid species were described from one or
two specimens. In Nicaraguan lakes, where morpho-
logically similar species occur, such an analysis has led
to confusion and controversy concerning taxonomic re-
lationships (Meek 1907, Villa 1976, Barlow and Munsey
1976, Stauffer et al. 1995). An approach that utilizes
multivariate analysis of shape (e.g., Atchley 1971,
Humphries et al. 1981, Reyment et al. 1984, Bookstein
et al. 1985) has yielded more reasonable hypotheses
(Stauffer and McKaye 2001).
Thus, we analyzed differ-
ences in body shape of the new
species and the type specimens
of previously described species
in the A. citrinellus complex
using sheared principal com-
ponent analysis (SPCA) of the
morphometric data (Hum-
phries et al., 1981; Bookstein et
al., 1985). The first principal
component of the morphomet-
ric data is interpreted as
a size component and
the sheared compo-
nents as shape, inde-
pendent of size (Hum-
phries et al., 1981; Book-
stein et al., 1985). Mer-
istic data were ana-
lyzed using principal
component analysis
Abbreviation Definition
ADAA Distance between anterior insertion of dorsal fin to anterior insertion of anal fin.
PDPA Distance between posterior insertion of dorsal fin to posterior insertion of anal fin.
ADPA Distance between anterior insertion of dorsal fin to posterior insertion of anal fin.
PDAA Distance between posterior insertion of dorsal fin to anterior insertion of anal fin.
PDVC Distance between posterior insertion of dorsal fin to ventral insertion of caudal fin.
PADC Distance between posterior insertion of anal fin to dorsal insertion of caudal fin.
ADP2 Distance between anterior insertion of dorsal fin to anterior insertion of pelvic fin.
PDP2 Distance between posterior insertion of dorsal fin to anterior insertion of pelvic fin.
Table 2. Definition of abbreviations for selected morphometrics.
Species Museum Status Number
Amphilophus citrinellus British Museum of Natural History syntypes 3
Amphilophus dorsatus Field Museum of Natural History Paratypes 2
Amphilophus labiatus British Museum of Natural History Syntypes 2
Amphilophus erythraeus British Museum of Natural History Holotype 1
Amphilophus granadensis Field Museum of Natural History Paratype 1
Amphilophus zaliosus California Academy of Sciences Paratypes 5
Table 1. Type specimens borrowed from museum for morphological analyses.
Cuadernos de Investigación de la
UCA / N° 12
5
Measurements Amphilophus citrinellus Amphilophus dorsatus
Mean St. Dev. Range Mean St. Dev. Range
Standard length, mm 135.2 0.4 130.2-139.5 96.9 18.4 83.9-109.9
Head length, mm 47.7 0.1 46.4-48.9 37.0 6.9 32.1-41.9
Percent of standard length
Head length 35.2 0.3 35.0-35.6 38.2 0.1 381-382
Snout to dorsal-fin origin 43.6 0.9 42.7-44.6 45.4 2.0 44.0-46.8
Snout to pelvic-fin origin 42.5 0.7 41.9-43.3 46.1 1.8 44.9-47.4
Caudal peduncal length 11.3 9.6 10.6-12.4 10.1 1.6 9.0-11.3
Least caudal peduncal depth 14.3 4.4 14.0-14.8 13.6 0.1 13.6-13.7
Pectoral-fin length
Pelvic-fin length
Dorsal-fin base length 63.3 0.4 63.0-63.9 59.1 2.1 57.6-60.6
ADAA 58.6 0.9 57.6-59.5 55.1 1.0 54.4-55.8
PDPA 16.0 0.5 15.6-16.6 16.1 0.1 16.0-16.2
ADPA 68.5 0.2 68.2-68.7 64.7 0.9 64.1-65.4
PDAA 40.5 1.2 39.2-41.6 37.0 0.3 36.8-37.2
PDVC 17.9 1.4 16.4-19.2 17.1 0 17.1
PADC 181.3 0.7 17.3-18.7 19.0 0.9 18.4-19.7
ADP2 45.9 1.2 44.9-47.3 45.7 1.0 45.0-46.4
PDP2 57.2 0.9 56.6-58.3 56.4 2.0 55.0-57.9
Percent head length
Horizontal eye diameter 28.8 0.4 28.4-29.2 32.2 1.3 33.9-35.7
Vertical eye diameter 28.4 1.2 27.2-29.6 30.4 0.6 30.0-30.9
Snout length 41.0 0.8 40.4-419 34.8 1.3 33.9-35.7
Postorbital head length 37.7 1.6 36.5-39.5 35.7 0.8 35.2-36.3
Preorbital depth 25.6 0.7 25.1-26.4 20.1 3.9 17.4-22.9
Lower-jaw length 42.7 3.9 39.2-41.6 43.5 0.4 43.3-43.8
Cheek depth 32.2 0.5 31.8-32.7 23.9 2.8 22.0-25.9
Head depth 115.7 3.8 111.5-118.9 92.6 3.3 90.3-94.9
Table 3. Morphometric values of Amphilophus citrinellus (syntypes, BMNH 1864.1.26.201-3; n=3) and
Amphilophus dorsatus (paratypes; FMNH 5970; n=2).
Counts Amphilophus citrinellus Amphilophus dorsatus
Mode % Freq. Range Mode % Freq. Range
Lateral-line scales 30 66.7 30-31 31 100 31
Pored scales posterior to lateral line 2 100 2 1-2
Scale rows on cheek 4 100 4 4 100 4
Dorsal-fin spines 17 66.7 16-17 17 100 17
Dorsal-fin rays 12 66.7 11-12 12 100 12
Anal-fin spines 3 100 3 7 100 7
Anal-fin rays 2 66.7 8-9 8-9
Pectoral-fin rays 15 100 15 15-16
Pelvic-fin rays 5 100 5 5 100 5
Gill rakers on first ceratobranchial 9 66.7 9-10 8 100 8
Gill rakers on first epibranchial 2 66.7 2-3 2 100 2
Teeth in outer row of left lower jaw 17-20 8-14
Teeth rows on upper jaw 3 100 3 2 100 2
Teeth rows on lower jaw 3 66.7 3-4 2 100 2
Table 4. Meristic values of Amphilophus citrinellus (syntypes, BMNH 1864.1.26.201-3; n=3) and
Amphilophus dorsatus (paratypes; FMNH 5970; n=2).
Size PC2
Standard length 0.19 0.05
Head length 0.18 0.17
Snout length 0.23 0.35
Post orbital head length 0.20 0.02
Horizontal eye diameter 0.10 0.04
Vertical eye diameter 0.11 0.10
Head depth 0.24 -0.31
Preorbital depth 0.27 0.55
Cheek depth 0.27 -0.11
Lower jaw length 0.12 0.44
Snout to dorsal-fin origin 0.17 0.19
Snout to pelvic-fin origin 0.17 0.05
Dorsal-fin base length 0.20 -0.08
ADAA 0.21 -0.03
ADPA 0.20 -0.07
PDAA 0.21 -0.07
PDPA 0.22 -0.06
PDVC 0.23 -0.05
PADC 0.20 -0.05
PDP2 0.23 -0.16
ADP2 0.21 -0.21
Caudal peduncle length 0.20 -0.21
Least caudal peduncle depth 0.20 -0.10
Table 5. Variable loadings on the size principal
components and second principal components
(shape factor) of the morphometric data for
the Amphilophus citrinellus complex.
Characters PC1
Dorsal spines 0.53
Dorsal rays -0.14
Anal rays -0.19
Pectoral rays -0.33
Lateral-line scales 0.27
Pored scales posterior to lateral line 0.36
Cheek scales 0.28
Gill rakers on first ceratobranchial 0.08
Gill rakers on first epibranchial 0.18
Teeth rows on upper jaw -0.36
Teeth rows on lower jaw -0.33
Table 6. Variable loadings on the first principal
component of the meristic data for Amphi-
lophus citrinellus complex.
(PCA) of the correlation matrix. Differences between
species were illustrated by plotting the sheared sec-
ond principal components of the morphometric data
against the first principal components of the meris-
tic data (Stauffer and Hert, 1992).
Cuadernos de Investigación de la
UCA / N° 12
6
Counts Amphilophus labiatus Amphilophus erythraeus Amphilophus granadensis
Mode % Freq. Range Holotype Holotype
Lateral-line scales 31 100 31 31 30
Pored scales posterior to lateral line 2 100 2 2 2
Scale rows on cheek 4 100 4 4 4
Dorsal-fin spines 17 100 17 17 17
Dorsal-fin rays 11 100 11 12 12
Anal-fin spines 7 100 7 7 7
Anal-fin rays 7-8 8 8
Pectoral-fin rays 14 100 14 15 15
Pelvic-fin rays 5 100 5 5 5
Gill rakers on first ceratobranchial 10 100 10 8 9
Gill rakers on first epibranchial 2-4 3 3
Teeth in outer row of left lower jaw 18-19 16 5
Teeth rows on upper jaw 3 100 3 3 1
Teeth rows on lower jaw 3 100 3 3 1
Table 8. Meristic values of Amphilophus labiatus (syntypes, BMNH 1867.9.23:7-8; n=2), Amphilophus erythraeus (holotype; BMNH
1865.7.20:33), and Amphilophus granadensis (paratype; FMNH 5950).
Measurements Amphilophus labiatus Amphilophus. erythraeus Amphilophus granadensis
Mean St. Dev. Range Holotype Holotype
Standard length, mm 135 7.9 129.4-140.6 130 121.3
Head length, mm 52 1.5 51.1-53.2 46.1 41.2
Percent of standard length
Head length 38.6 1.2 37.8-39.5 35.5 34.0
Snout to dorsal-fin origin 46.7 0.4 46.4-47.0 42.6 41.0
Snout to pelvic-fin origin 45.2 0.9 4.46-4.59 42.8 46.9
Caudal peduncal length 11.1 1.3 10.2-12.0 11.7 10.9
Least caudal peduncal depth 13.6 0.1 13.5-13.7 13.0 15.0
Dorsal-fin base length 55.8 2.1 54.4-57.3 59.0 59.2
ADAA 54.0 2.2 52.5-55.6 54.0 54.6
PDPA 15.7 1.6 14.6-16.9 15.7 16.6
ADPA 61.7 0.2 61.6-61.9 61.7 63.6
PDAA 34.7 2.3 333.1-36.3 34.7 36.8
PDVC 17.4 0.7 16.9-17.9 17.4 19.0
PADC 18.1 0.8 17.5-18.7 18.1 17.8
ADP2 41.8 2.1 40.4-43.3 41.8 43.9
PDP2 54.3 3.7 51.7-56.9 54.3 36.5
Percent head length
Horizontal eye diameter 25.5 0.4 25.2-25.8 26.9 30.8
Vertical eye diameter 24.6 2.3 23.0-26.3 26.1 30.0
Snout length 43.1 0.4 42.8-43.4 37.8 40.5
Postorbital head length 35.9 0.5 35.6-36.3 35.7 38.5
Preorbital depth 23.4 2.1 22.0-24.9 38.4 23.2
Lower-jaw length 43.4 2.4 41.7-45.1 42.3 41.3
Cheek depth 26.2 2.3 24.6-27.8 27.4 29.4
Head depth 85.4 77.8 79.9-90.9 101.3 108.1
Table 7. Morphometric values of Amphilophus labiatus (syntypes, BMNH 1867.9.23:7-8; n=2), Amphilophus erythraeus (holotype; BMNH
1865.7.20:33), and Amphilophus granadensis (paratype; FMNH 5950).
Results
We only measured a subset of the type series of pre-
viously described species of the A. citrinellus complex
(Tables 2-8); however, based on these data there is no
overlap among the minimum polygon clusters when
the sheared second principal components (morphomet-
ric data) are plotted against the first principal compo-
Cuadernos de Investigación de la
UCA / N° 12
7
Figure 4. Holotype (PSU 3448.1) of Amphilophus amarillo.
Figure 5. A pair of Amphilophus amarillo guarding their offspring in a rocky habitat along the western shore of Lake Xiloá (photo by Ad
Konings).
Cuadernos de Investigación de la
UCA / N° 12
8
nents of the meristic data (Fig. 6). Size accounted for
88.5% and the second principal component accounted
for 3.2% of the total variance of the morphometric data.
Those variables that had the highest loadings
on the sheared second principal component
were preorbital depth, lower jaw length, and
snout length (Table 5). The parameters that
had the highest loadings on the first principal
component of the meristic data were dorsal-
fin spines, post lateral-line scales, and teeth
rows on the upper jaw (Table 6).
Amphilophus amarillo, n. sp.
(Fig. 4)
Holotype. – Penn State University Fish Mu-
seum (PSU) 3448.1, adult male, 154.6 mm SL
from Agua caliente, Lake Xiloá (N 12° 13,848'
W 86° 19,387'); Field No. JRS-93-64, 18 Octo-
ber, 1993 (3-10 m).
Paratypes. – PSU 3448 (6 specimens, 107.6-
142.2 mm SL); data as for holotype.
Diagnosis. – Amphilophus amarillo has a
shorter snout (35.3-40.1% SL) and dorsal-fin
base length (57.0-61.9% SL) than A. citrinellus
(40.4-41.9%, 63.0-63.9% SL, respectively) and
a shorter snout than Amphilophus granadensis
(Meek) (40.5%SL). Amiphilophus amarillo has
a shorter head (34.5-36.8% SL) than A. dorsatus
(38.1-38.2% SL) and A. labiatus (37.8-39.5% SL).
Body depth as measured by ADP2 is greater
in A. amarillo (43.7-49.0% SL) than in either
Amphilophus erythraeus
(Günther) (41.8% SL) or A.
granadensis (36.5% SL).
Description. – Principal mor-
phometric ratios are given in
Table 9 and meristic values in
Table 10. Both males and fe-
males are colored similarly
(Fig. 5). Head with green
ground coloration with yel-
low highlights; below cheek
head is yellow; anterior por-
tion of gular yellow, posterior
portion red/orange. Interor-
bital region green with two
dark green interorbital bars;
preopercle green; posterior
portion of opercle red/yel-
low/orange. Dorsally to up-
per lateral line, green with yel-
low highlights in some indi-
viduals and yellow in others;
middle 1/3 of lateral side yellow; ventral 1/3 green/
yellow; 6-8 black bars that appear as extension of mid-
black spots, the anterior bars extend into dorsal fin;
Figure 6. Plot of individual sheared second principal component scores (morphometric data) and
the first principle component scores (meristic data) of a subset of the type series of the A. citrinellus
complex.
Measurements Holotype Mean St. Dev. Range
Standard length 154.6 125.8 15.9 107.6-154.6
Head length, mm 55.9 44.7 6.2 37.9-55.9
Percent of standard length
Head length 36.2 35.5 0.75 34.5-36.8
Snout to dorsal-fin origin 43.7 43.0 1.9 40.3-46.7
Snout to pelvic-fin origin 44.2 44.1 1.1 41.8-45.2
Caudal peduncal length 12.8 12.1 1.5 9.9-14.8
Least caudal peduncal depth 13.8 14.1 0.4 13.7-14.7
Dorsal-fin base length 61.1 59.7 1.8 57.0-61.9
ADAA 58.7 55.7 2.6 52.6-60.2
PDPA 16.3 16.2 0.7 15.4-17.4
ADPA 66.9 65.8 1.9 63.5-68.2
PDAA 37.2 37.4 1.3 35.1-39.5
PDVC 19.5 18.1 0.9 16.6-19.5
PADC 18.5 18.8 0.7 18.0-19.6
ADP2 47.7 46.4 1.8 43.7-49.0
PDP2 59.0 57.6 1.1 56.0-59.0
Percent head length
Horizontal eye diameter 25.8 28.8 2.6 25.8-32.5
Vertical eye diameter 25.9 27.7 1.9 25.6-30.8
Snout length 40.1 37.9 1.7 35.3-40.1
Postorbital head length 40.3 38.1 1.3 35.9-40.3
Preorbital depth 25.3 22.9 1.7 20.6-25.3
Lower-jaw length 36.9 40.6 2.0 36.9-43.3
Cheek depth 33.0 30.1 2.2 26.7-33.3
Head depth 102.8 106 4.2 102-113
Table 9. Morphometric values of Amphilophus amarillo (PSU 3448; PSU 3448.1;
n=8; mean includes holotype).
Cuadernos de Investigación de la
UCA / N° 12
9
black caudal spot that extends onto caudal fin. Belly
yellow-green with black highlights. Dorsal fin green/
gray; posterior rays orange in some individuals. Cau-
dal fin with gray rays and clear membranes with or-
ange highlights. Distal portion of anal-fin spines black,
majority of anal-fin membranes green/gray with pos-
terior portion orange. Pelvic fins green/gray
with first ray black. Pectoral fins with clear
membranes and rays with faint yellow
markings on rays.
Etymology. – Specific epithet from Span-
ish meaning yellow to denote the yellow
highlights throughout. A noun in apposi-
tion.
Amphilophus xiloaensis, n. sp.
(Fig. 7)
Holotype. – PSU3381.1, adult male, 147.6
mm SL from the southeastern shore of Lake
Xiloá (N 12° 12,793' W 86° 19,028'), Field
No. JRS-00-121, 18 December, 2000 (2-8 m)
Paratypes. – PSU3381, data as for holo-
type, (1 specimen, 124.3 mm); PSU3384, (5
specimens, 137.2-158.6 mm) Lake Xiloá, in front of Club
Nautico (N 12° 12,907' W 86° 19,418'), Field No. JRS-
93-67, 19 October, 1993.
Diagnosis. – Amphilophus xiloaensis has a smaller eye
(HED – 26.6-27.3%SL; VED – 24.4-26.1%SL) than A.
citrinellus (HED – 28.4-29.2%SL; VED – 27.2-29.6%SL),
A. dorsatus (HED – 33.9-35.7%SL; VED – 30.0-
30.9%SL) and A. granadensis (HED – 30.8%SL;
VED – 30.0%SL). Amphilophus xiloaensis (34.2-
37.0%SL) has a shorter head than A. labiatus
(37.8-39.5%SL). Amphilophus xiloaensis has a
deeper body as evidenced by ADPA (64.4-
71.0%SL) and PDAA (37.3-40.1%SL) than ei-
ther A erythraeus (ADPA – 61.7%SL; PDAA –
34.7%SL) or A granadensis (ADPA – 63.6%SL;
PDAA 36.8%SL). Amphilophus xiloaensis has 9-
11 gill rakers on the first ceratobranchial, while
A. amarillo has 7-8.
Description. – Principal morphometric ratios
are given in Table 11 and meristic values in
Table 12. Both males and females are colored
similarly (Fig. 8), and there are gold morphs
(Figs. 9-10) of both sexes. Some forms have a
gray/green head with single black interorbital
bar and red gular. Laterally gray ground color
with six black vertical bars and caudal spot
that extends onto caudal fin; white belly. Dor-
sal, caudal, and anal fins gray with lighter
spots. Pelvic fins gray with black leading edge.
Pectoral fins clear. Other colored forms with
yellow head and white cheek, white opercle
with yellow/green highlights, and white gu-
lar with red blotches. Laterally bright orange
with white shoulder. Dorsal fin orange with
Counts Holotype Mode % Freq. Range
Lateral-line scales 30 30 50 30-32
Pored scales posterior to lateral line 2 2 75 1-2
Scale rows on cheek 4 4 87.5 3-4
Dorsal-fin spines 17 17 62.5 16-17
Dorsal-fin rays 11 11-12
Anal-fin spines 7 7 87.5 6-7
Anal-fin rays 8 8 75 7-9
Pectoral-fin rays 15 15 62.5 15-16
Pelvic-fin rays 5 5 100
Gill rakers on first ceratobranchial 7 7 62.5 7-8
Gill rakers on first epibranchial 2 2 75 1-3
Teeth in outer row of left lower jaw 11 11 50 11-13
Teeth rows on upper jaw 3 3 87.5 2-3
Teeth rows on lower jaw 3 3 50 2-4
Table 10. Meristic values of Amphilophus amarillo (PSU 3448.1; PSU 3348; n=8;
mode includes holotype).
Measurements Holotype Mean St. Dev. Range
Standard length 141.6 145.9 15.0 124.3-170.5
Head length, mm 52.6 52.2 4.9 45.1-58.7
Percent of standard length
Head length 35.6 35.8 0.92 34.2-37.0
Snout to dorsal-fin origin 43.3 42.9 1.5 39.9-44.1
Snout to pelvic-fin origin 41.4 44.1 1.4 41.4-45.4
Caudal peduncal length 12.0 11.6 0.6 11.0-12.5
Least caudal peduncal depth 13.8 14.4 0.4 13.8-15.2
Dorsal-fin base length 62.2 61.3 2.5 58.2-65.3
ADAA 54.9 57.7 3.1 53.5-62.2
PDPA 17.3 17.0 0.5 16.4-17.6
ADPA 66.3 67.0 2.4 64.4-71.0
PDAA 38.9 38.9 1.1 37.3-40.1
PDVC 18.1 18.7 0.9 17.6-19.9
PADC 19.7 19.2 0.8 18.1-20.3
ADP2 45.5 48.8 2.4 45.5-52.1
PDP2 58.8 60.9 1.8 58.8-63.5
Percent head length
Horizontal eye diameter 26.8 26.8 0.3 26.6-27.3
Vertical eye diameter 25.3 25.4 0.6 24.4-26.1
Snout length 41.9 39.5 2.2 36.1-42.5
Postorbital head length 36.6 38.4 2.0 36.6-47-1.7
Preorbital depth 22.9 24.1 1.0 22.9-25.8
Lower-jaw length 37.9 36.6 1.3 33.9-37.9
Cheek depth 29.2 31.1 2.1 28.6-34.1
Head depth 115.2 118.6 6.4 113.5-131.6
Table 11. Morphometric values of Amphilophus xiloaensis (n=7 and includes
holotype).
Cuadernos de Investigación de la
UCA / N° 12
10
Figure 7. Holotype (PSU3381) of Amphilophus xiloaensis.
Figure 8. A pair of Amphilophus xiloaensis defending their offspring in Lake Xiloá (Photo by Ad Konings).
Cuadernos de Investigación de la
UCA / N° 12
11
Figure 10. Gold pair of Amphilophus xiloaensis protecting their brood in Lake Xiloá (photo by Ad Konings).
Figure 9. A mixed gold/normal pair of Amphilophus xiloaensis in Lake Xiloá (photo by Ad Konings).
Cuadernos de Investigación de la
UCA / N° 12
12
white patches. Caudal fin orange with white tips. Anal
fin orange with white lappets. Pectoral fins orange with
posterior one-quarter white. Pelvic fins orange, with
spine and 1st ray white and 2nd ray red. Other individu-
als mostly white with orange blotches, while others
were bright orange.
Etymology. – Specific epithet references the type lo-
cality Lake Xiloá. An adjective.
Amphilophus sagittae, n. sp.
(Fig. 11)
Holotype. – PSU3386.1, adult male, 157.2
mm SL from from Agua caliente Lake Xiloá
(N 12° 13,848' W 86° 19,387'), Field No. JRS-
93-64, 18 October, 1993 (3-10 m).
Paratypes. – PSU 3386, (5 specimens, 144.0-
159.1 mm SL), data as for holotype; PSU3383
(2 specimens 129.6-159.8 mm SL), Field No.
JRS-00-121, 17 December, 2000; PSU82 (5
specimens 121.2-160.3 mm SL), Field No. JRS-
00-122, 18 December, 2000; from Lake Xiloá
(N 12° 12,793' W 86° 19,028').
Diagnosis. – Amphilophus sagittae has a more
streamlined body, as indicated by the smaller
snout to dorsal-fin origin (38.6-41.9%SL) and
ADAA (49.7-53.8%SL) (Table 14) than A.
citrinellus (42.7-44.6%SL; 57.6-59.5%SL), A
dorsatus (44.0-46.8%SL; 54.4-55.8%SL), A.
labiatus (46.4-47.0%SL; 52.5-55.6%SL), A.
erythraeus (42.6%SL; 54.0%SL), A. granadensis
(41.0%SL; 54.6%SL), and A. amarillo (40.3-
46.7%SL; 52.6-60.2%SL). Amphilophus sagittae
has a longer caudal peduncal length (11.4-
14.0%SL) than A. granadensis (10.9%SL).
Amphilophus sagittae has a smaller ADP2
(39.3-43.4%SL) than A. xiloaensis (45.5-
52.1%SL). Amphilophus sagittae morphologi-
cally resembles Amphilophus zaliosus Barlow
from Lake Apoyo. The PDPA for A. sagittae
(15.4-17.9%SL) is greater than that of A.
zaliosus (13.7-15.5%SL; Table 15 & 16).
Description. – Principal morphometric ra-
tios are given in Table 13 and meristic val-
ues in Table 14. Both males and females are
colored similarly (Figs. 14, 15). Head is dark
green dorsally, black laterally and with a
black gular, although some specimens with
a red gular. Laterally black with green high-
lights and 5 black bars. Ventrally black an-
terior to P2 and white posterior to P2. Dor-
sal, caudal, anal, and pelvic fins black. Pec-
toral fins with black rays and clear mem-
branes.
Etymology. – Specific epithet is a noun in apposition,
from Latin sagitta or sagittae meaning arrow, which
denotes the slender shape of this species when com-
pared to other Amphilophus species found in Lake Xiloá.
Counts Holotype Mode % Freq. Range
Lateral-line scales 32 30 57.1 30-32
Pored scales posterior to lateral line 2 2 57.1 0-2
Scale rows on cheek 4 4 100
Dorsal-fin spines 17 16 71.4 16-17
Dorsal-fin rays 12 12 71.4 11-12
Anal-fin spines 7 7 57.4 6-7
Anal-fin rays 8 8 71.4 8-9
Pectoral-fin rays 15 15/16 42.9 15-17
Pelvic-fin rays 5 5 100
Gill rakers on first ceratobranchial 9 9 85.7 9-11
Gill rakers on first epibranchial 3 3 85.7 2-3
Teeth in outer row of left lower jaw 14 11 42.9 10-14
Teeth rows on upper jaw 4 4 71.4 3-4
Teeth rows on lower jaw 4 4 85.7 3-4
Table 12. Meristic values of Amphilophus xiloaensis (n=7 and mode includes holotype).
Measurements Holotype Mean St. Dev. Range
Standard length 157.2 150.9 12.7 121.2-163.1
Head length, mm 53.8 51.8 4.3 42.8-55.8
Percent of standard length
Head length 34.2 34.4 0.7 33.1-35.3
Snout to dorsal-fin origin 39.1 40.3 1.0 38.6-41.9
Snout to pelvic-fin origin 40.8 42.0 2.5 38.7-47.5
Caudal peduncal length 12.7 12.6 0.7 11.4-14.0
Least caudal peduncal depth 14.5 14.0 0.4 13.5-14.9
Dorsal-fin base length 60.3 59.9 1.5 55.4-61.7
ADAA 52.2 52.1 1.3 49.7-53.8
PDPA 16.6 16.7 0.7 15.4-17.9
ADPA 65.3 64.7 1.9 59.4-66.8
PDAA 36.7 37.4 1.8 31.9-39.6
PDVC 18.9 18.2 0.9 16.4-19.3
PADC 19.2 19.4 0.6 18.5-20.6
ADP2 40.7 41.8 1.3 39.3-43.4
PDP2 55.8 58.0 1.9 54.0-60.1
Percent head length
Horizontal eye diameter 27.0 27.1 1.3 25.0-29.1
Vertical eye diameter 26.9 25.6 1.5 23.2-27.4
Snout length 39.7 38.5 2.0 35.0-42.2
Postorbital head length 39.8 39.4 1.6 37.1-42.1
Preorbital depth 23.5 22.8 1.0 21.2-24.2
Lower-jaw length 35.0 38.4 1.9 35.0-42.0
Cheek depth 29.1 28.7 2.0 24.9-31.7
Head depth 97.7 105.0 3.8 97.7-110.5
Table 13. Morphometric values of Amphilophus sagittae (n=13 and includes
holotype).
Cuadernos de Investigación de la
UCA / N° 12
13
Counts Holotype Mode % Freq. Range
Lateral-line scales 30 31 38.5 30-35
Pored scales posterior to lateral line 1 2 92.3 1-2
Scale rows on cheek 5 5 76.9 4-5
Dorsal-fin spines 17 17 69.2 16-17
Dorsal-fin rays 11 11 61.5 11-12
Anal-fin spines 6 7 67.5 6-7
Anal-fin rays 9 9 53.8 8-10
Pectoral-fin rays 5 16 38.5 14-17
Pelvic-fin rays 15 5 100
Gill rakers on first ceratobranchial 10 11 46.2 8-12
Gill rakers on first epibranchial 3 2 76.9 2-3
Teeth in outer row of left lower jaw 11 12 46.2 10-12
Teeth rows on upper jaw 4 4 92.3 3-4
Teeth rows on lower jaw 4 4 61.5 3-5
Table 14. Meristic values of Amphilophus sagittae(n=13 and mode includes holotype).
Discussion
The SPCA of the morphometric data and PCA of the
meristic data of the known species in the A. citrinellus
species complex result in the minimum polygon clus-
ters shown in Fig. 12. Amphilophus sagittae is quite dis-
tinct from the other forms; thus, the minimum poly-
gon clusters of the other two newly described species
overlap with each other. When the data for
A. sagittae is removed from the analysis, the
two other new species from Lake Xiloá are
closely grouped with A. citrinellus. When A.
citrinellus, A. amarillo, and A. xiloaensis are
analyzed separately the minimum polygon
clusters among the species do not overlap
(Fig. 13). Size accounted for 90% and the sec-
ond principal component for 2.9% of the
total variance of the morphometric data.
Those variables that had the highest load-
ings on the sheared second principal com-
ponent were caudal peduncle length and
head depth (Table 17). The characters that
had the highest loadings on the first princi-
pal component of the meristic data were gill
rakers and teeth rows (Table 18).
Amphilophus sagittae from Lake Xiloá
closely resembles A. zaliosus from Lake Apoyo. The
minimum polygon clusters formed by plotting the
sheared second principal components of the morpho-
metric data against the first principal components of
the meristic data do not overlap (Fig. 16). Size ac-
counted for 94% and the second principal component
accounted for 2.3% of the total variance of the mor-
phometric data. Those variables that had the highest
loadings on the sheared second principal component
are least caudal peduncle depth, dorsal-fin base length,
and PDPA (Table 19). The parameters that had the high-
est loadings on the first principal component of the
meristic data were dorsal-fin elements and gill rakers
(Table 20).
More research on the Amphilophus species in the lakes
of Nicaragua is desperately needed. Waid et al. (1999)
reported the presence of A. citrinellus in eight crater
lakes in the Great Lakes Basin of Nicaragua. It may be
Measurements Mean St. Dev. Range
Standard length 119.2 6.6 110-124
Head length, mm 39.8 2.6 36.2-42.3
Percent of standard length
Head length 33.4 0.7 32.5-34.0
Snout to dorsal-fin origin 38.8 1.1 37.3-40.1
Snout to pelvic-fin origin 41.5 0.8 40.6-42.6
Caudal peduncal length 14.6 1.2 13.3-16.3
Least caudal peduncal depth 12.7 1.7 11.2-15.5
Dorsal-fin base length 57.4 1.7 55.8-59.8
ADAA 48.7 2.9 45.7-53.3
PDPA 14.2 0.9 13.7-15.5
ADPA 60.9 2.5 57.1-64.1
PDAA 32.9 0.6 32.0-33.7
PDVC 18.4 1.1 17.1-20.0
PADC 18.3 1.0 16.8-19.5
ADP2 39.2 2.0 36.8-41.5
PDP2 54.4 17.0 51.6-56.2
Percent head length
Horizontal eye diameter 27.6 1.8 25.6-29.9
Vertical eye diameter 27.0 1.9 24.9-29.2
Snout length 36.3 1.1 35.2-37.8
Postorbital head length 37.9 0.8 37.1-39.2
Preorbital depth 21.2 1.0 20.0-22.4
Lower-jaw length 37.8 1.7 35.2-39.5
Cheek depth 26.7 0.4 26.3-27.3
Head depth 96.1 10.5 81.2-108.4
Table 15. Morphometric values of Amphilophus zaliosus (paratypes,
CAS29105; n=5).
Counts Mode % Freq. Range
Lateral-line scales 32 60 31-32
Pored scales posterior to lateral line 2 80 2-3
Scale rows on cheek 5 80 5-6
Dorsal-fin spines 17 60 16-17
Dorsal-fin rays 12 60 11-13
Anal-fin spines 7 60 6-7
Anal-fin rays 8 60 8-9
Pectoral-fin rays 15 80 13-15
Pelvic-fin rays 5 100
Gill rakers on first ceratobranchial 11 80 10-11
Gill rakers on first epibranchial 3 60 2-3
Teeth in outer row of left lower jaw 15 40 12-16
Teeth rows on upper jaw 4 100
Teeth rows on lower jaw 3 80 3-4
Table 16. Meristic values of Amphilophus zaliosus (paratypes,
CAS29105; n=5).
Cuadernos de Investigación de la
UCA / N° 12
14
Figure 11. Holotype (PSU3386.1) of Amphilophus sagittae.
Figure 13. Plot of individual sheared second principal component scores
(morphometric data) and the first principle component scores (meristic data) of
a subset of the type series of the Amphilophus citrinellus, Amphilophus xiloaensis,
and Amphilophus amarillo.
Figure 12. Plot of individual sheared second principal component scores
(morphometric data) and the first principle component scores (meristic data) of
a subset of the type series of the A. citrinellus complex, including Amphilophus
sagittae.
Size PC2
Standard length -0.19 0.06
Head length -0.19 0.02
Snout length -0.24 -0.13
Post orbital head length -0.20 0.07
Horizontal eye diameter -0.12 0.20
Vertical eye diameter -0.14 0.06
Head depth -0.18 -0.32
Preorbital depth -0.27 -0.17
Cheek depth -0.24 -0.16
Lower jaw length -0.17 -0.03
Snout to dorsal-fin origin -0.17 -0.12
Snout to pelvic-fin origin -0.19 0.04
Dorsal-fin base length -0.20 -0.13
ADAA -0.22 -0.12
ADPA -0.21 -0.09
PDAA -0.20 -0.16
PDPA -0.23 0.04
PDVC -0.25 0.05
PADC -0.21 0.21
PDP2 -0.21 0.04
ADP2 -0.21 -0.08
Caudal peduncle length -0.21 0.80
Least caudal peduncle depth -0.20 0.01
Table 17. Variable loadings on the size principal
components and second principal components (shape
factor) of the morphometric data for Amphilophus
citrinellus, Amphilophus amarillo, and Amphilophus
xiloaensis.
Cuadernos de Investigación de la
UCA / N° 12
15
Fig 14. A fry-guarding pair Amphilophus sagittae in Lake Xiloá (photo by Ad Konings).
Fig 15. A gold-colored pair Amphilophus sagittae leading their offspring in Lake Xiloá (photo by Ad Konings).
Cuadernos de Investigación de la
UCA / N° 12
16
that we are observing multiple species within
each of the crater lakes. For example, A.
zaliosus, the Arrow Cichlid from Lake Apoyo,
is piscivorous and morphologically resembles
A. sagittae; however, it appears to be geneti-
cally closer to all other species in Lake Apoyo
than to the A. sagittae in Lake Xiloá (McKaye et al., 1998).
Our genetic data (Stauffer et al. 1995, McKaye et al. 1998)
indicate that all of the species within both Lake Xiloá
and Lake Apoyo are more closely related to each other
than to the phenotypically similar forms in the differ-
ent lakes. This suggests that the similar morphologies
are due to convergence (Kocher et al. 1993), and that
sympatric speciation may indeed be occurring in each
of the crater lakes (McKaye 1980). McKaye et al. (1998)
reported on the genetic similarity of these cichlids in
the two lakes and these results have been supported
by subsequent research (Wilson et al. 2000).
Nicaragua is of geologically recent origin. The re-
gion was formed in the late Cretaceous or early Pale-
ocene (Villa, 1982). This implies that the great basin of
Nicaraguan lakes (Fig.1), is of recent formation, and so
its ichthyofauna. Rapid allopatric and intralacustrine
speciation might be taking place within this species
group. Further careful research examining the behav-
ior, morphology and genetics of these fishes is required
to determine the phylogeny and species composition
of this species complex. McKaye et al. (this volume)
compares and contrasts behavioral and genetic infor-
mation of the Lake Xiloá species.
Acknowledgments
We thank the following students of the University
of Central America for their participation in the prepa-
ration of specimens used in this study: Silvio Pereira,
Characters PC1
Dorsal spines -0.15
Dorsal rays 0.14
Anal rays 0.16
Pectoral rays 0.20
Lateral-line scales 0.04
Pored scales posterior to lateral line -0.17
Cheek scales 0.29
Gill rakers on first ceratobranchial 0.48
Gill rakers on first epibranchial 0.49
Teeth rows on upper jaw 0.41
Teeth rows on lower jaw 0.37
Table 18. Variable loadings on the first principal
component of the meristic data for Amphilophus
citrinellus, Amphilophus amarillo, and Amphilophus
xiloaensis.
Figure 16. Plot of individual sheared second principal component scores
(morphometric data) and the first principle component scores (meristic data) of
a subset of the type series of the Amphilophus zaliosus (also in the legend above)
and Amphilophus sagittae.
Carolina López, Sonia Wheelock, Roberto Rivas, and
Enrique Campbell. This research was supported by the
United States National Science Foundation, United
States Agency for International Development. K.R.
McKaye was supported by the Fulbright program dur-
ing the course of this research. We thanks Ad Konings
for providing the in situ photographs.
Literature Cited
ATCHLEY, W. R. 1971. A comparative study of the causes
and significance of morphological variation in adults
and pupae of Culicoides: a factor analysis and mul-
tiple regression study. Evolution 25: 563-583.
BAREL, C., M. VAN OIJEN, F. WITTE, and E. WITTE-MAAS.
1977. An introduction to the taxonomy and morphol-
ogy of the haplochromine Cichlidae from Lake
Victoria. Netherlands Journal of Zoology 27: 333-389.
BANIC. 1977. Informe Financiero 1976. Banco Nicara-
güense de Industria y Comercio, Managua, Nicara-
gua. 46p.
BARLOW, G.W. 1976. The Midas Cichlids in Nicaragua.
p. 333-358 in: T.B. Thorson (ed.) Investigations of the
Ichthyofauna of Nicaraguan lakes. University of Ne-
braska, Lincoln.
BARLOW, G.W., J. R. BAYLIS, and D. ROBERTS. 1976. Chemi-
cal analyses of some crater lakes in relation to adja-
cent Lake Nicaragua. pp 17-20. in T.B. Thorson (ed.)
Investigations of the Ichthyofauna of Nicaraguan lakes.
University of Nebraska, Lincoln.
Cuadernos de Investigación de la
UCA / N° 12
17
Size PC2
Standard length -0.20 0.10
Head length -0.18 0.10
Snout length -0.27 0.27
Post orbital head length -0.19 -0.08
Horizontal eye diameter -0.10 -0.26
Vertical eye diameter -0.13 -0.17
Head depth -0.21 -0.35
Preorbital depth -0.25 0.22
Cheek depth -0.26 0.18
Lower jaw length -0.20 0.10
Snout to dorsal-fin origin -0.20 0.20
Snout to pelvic-fin origin -0.19 0.13
Dorsal-fin base length -0.19 -0.60
ADAA -0.23 0.02
ADPA -0.23 0.08
PDAA -0.20 -0.15
PDPA -0.18 -0.38
PDVC -0.27 0.29
PADC -0.19 -0.04
PDP2 -0.19 -0.12
ADP2 -0.21 -0.12
Caudal peduncle length -0.14 0.25
Least caudal peduncle depth -0.17 -0.43
Table 19. Variable loadings on the size principal
components and second principal components (shape
factor) of the morphometric data for Amphilophus
sagittae and Amphilophus zaliosus.
Characters PC1
Dorsal spines 0.51
Dorsal rays 0.36
Anal rays 0.32
Lateral-line scales -0.03
Pored scales posterior to lateral line 0.07
Cheek scales 0.37
Gill rakers on first ceratobranchial 0.36
Gill rakers on first epibranchial -0.48
Table 20. Variable loadings on the first principal
component of the meristic data for Amphilophus
sagittae and Amphilophus zaliosus.
BARLOW, G.W. and J.W. MUNSEY. 1976. The Red Devil-
Midas Cichlid species complex in Nicaragua. pp.
359-370. in T.B. Thorson (ed.) Investigations of the Ich-
thyofauna of Nicaraguan lakes. University of Nebraska,
Lincoln.
BOOKSTEIN, F., B. CHERNOFF, R. ELDER, J. HUMPHRIES, G.
SMITH, and R. STRAUSS. 1985. Morphometrics in evo-
lutionary biology. Academy of Natural Sciences, Spe-
cial Publication 15, Philadelphia.
BUSSING, W. A. and M. MARTIN. 1975. Systematic status,
variation, and distribution of four middle American
cichlid fishes belonging to the Amphilophus species
group, genus Cichlasoma. Natural History Museum Los
Angeles County Contributions in Science 269: 1-41.
GILL, T. and J.F. BRANSFORD. 1877. Synopsis of the fishes
of Lake Nicaragua. Proceedings of the Academy of Natu-
ral Sciences Philadelphia 29: 175-191.
GÜNTHER, A. 1869. An account of the fishes of the states
of Central America, based on collections made by
Capt. J. M. Dow, F. Godman, Esq., and O. Salvin,
Esq. Transactions of the Zoological Society London 6: 377-
494.
HUMPHRIES, J., F. BOOKSTEIN, B. CHERNOFF, G. SMITH, R.
ELDER, and S. POSS. 1981. Multivariate discrimination
by shape in relation to size. Systematic Zoology 30:
291-308.
JORDAN, D.S., B. W. EVERMANN, and H. W. CLARK. 1930.
Check list of the fishes and fishlike vertebrates of
North and Middle American, north of the northern
boundary of Venezuela and Colombia. Report of the
United States Commissioner of Fisheries for the year 1928,
Part 2 [1930]: 1-670.
KOCHER, T.D., J. A. CONROY, K. R. MCKAY E, and J. R.
STAUFFER, JR. 1993. Similar morphologies of cichlid
fish in lakes Tanganyika and Malawi are due to con-
vergence. Molecular Phylogenetics and Evolution 2: 158-
165.
KULLANDER, S.O. and K.E. HARTEL. 1997. The systematic
status of cichlid genera described by Louis Agassiz
in 1959: Amphilophus, Baiodon, Hypsophrys, and
Parachromis (Teleostei: Cichlidae). Ichthyological Ex-
plorations of Freshwaters 7: 193-202.
MCKAYE , K.R. 1980. Seasonality in habitat selection by
the gold color morph of Cichlasoma citrinellum and
its relevance to sympatric speciation in the family
Cichlidae. Environmental Biology of Fishes 5(1): 75-78.
MCKAYE , K. R. 1984. Behavioural aspects of cichlid re-
productive strategies: Patterns of territoriality and
brood defense in Central American substratum
spawners versus African mouth brooders. 245-273.
In: R. J. Wootton & C. W. Potts (eds.). Fish Reproduc-
tion: Strategies and Tactics. Academic Press, London.
MCKAYE , K.R. and G.W. BARLOW. 1976. Competition be-
tween color morphs of the Midas Cichlid, Cichlasoma
citrinellum, in Lake Jiloá, Nicaragua, pp. 465-475. In:
T.B. Thorson (ed.) Investigations of the Ichthyofauna of
Nicaraguan Lakes, University of Nebraska, Lincoln,
Nebraska.
MCKAYE , K.R., E.P. VAN DEN BERGHE, T.D. KOCHER, and
J.R. STAUFFER JR. 1998. Assortative mating by taxa of
the Midas Cichlid: ‘Cichlasoma’ citrinellum: Sibling
species or taxa speciating? Tropical Fish Biology: An
International Symposium. p. 38. University of
Cuadernos de Investigación de la
UCA / N° 12
18
Southampton, United Kingdom.
MEEK, S.E. 1907. Synopsis of the fishes of the great lakes
of Nicaragua. Field Columbia Museum, Zoological Se-
ries 7: 97-132.
MILLER, R. R. 1966. Geographic distribution of Central
American freshwater fishes. Copeia 1966: 773-802.
MURRY, B.A., E.P. VAN DEN BERGHE, and K.R. MCKAYE.
2001. Brood defense behavior of three sibling spe-
cies in the Amphilophus citrinellus species complex in
Lake Xiloa, Nicaragua. Journal of Aquariculture and
Aquatic Sciences 9: 134-149.
REGAN, C. T. 1906-1908. Biologia Centrali-Americana.
Pisces. London, Vol 8: 203 pp.
REYMENT, R., R. BLACKITH, and N. CAMBELL. 1984. Multi-
variate Morphometrics. Academic Press, New York.
ROE, K.J., D. CONKEL, and C. LYDEARD. 1997. Molecular
systematics of the Central American cichlid fishes
and the evolution of trophic-types in ‘Cichlasoma
(Amphilophus)’ and ‘C. (Thorichthys)’. Molecular
Phylogenetics and Evolution. 7: 366-376.
STAUFFER, J.R. JR. 1991. Description of a facultative
cleanerfish (teleostei: Cichlidae) from Lake Malawi,
Africa. Copeia 1991: 141-147.
STAUFFER, J. R., JR., N. J. BOWERS, K. R. MCKAYE , and T. D.
KOCHER. 1995. Evolutionarily significant units among
cichlid fishes: The role of behavioral studies. Ameri-
can Fisheries Society Symposium 17: 227-244.
STAUFFER, J.R. JR. and E. HERT. 1992. Pseudotropheus
callainos, a new species of mbuna (Cichlidae), with
analyses of changes associated with two intra-
lacustrine transplantations in Lake Malawi, Africa.
Ichthyological Explorations of Freshwaters 3: 253-264.
STAUFFER, J.R. JR. and K.R. MCKAYE. 2001. The naming of
cichlids. Journal of Aquariculture and Aquatic Sciences.
Cichlid Research: State of the Art. IX: 1-16.
STIASSNY, M.L.J. 1991. Phylogenetic intrarelationships of
the family Cichlidae. p. 1-31. in: Keenleyside, M.H.A.
(ed.) Cichlid Fishes: Behaviour, Ecology, and Evolution.
Chapman & Hall, London.
VILLA, J. 1968. Una teoría sobre el origen de los peces
de Xiloá. Encuentro: Rev. Univ. Centroamericana
1(4): 202-214.
VILLA, J. 1976. Systematic status of the cichlid fishes
Cichlasoma dorsatum, C. granadense, and C. nigritum
Meek, pp 375-383. In: T.B. Thorson (ed.) Investiga-
tions of the Ichthyofauna of Nicaraguan lakes. Univer-
sity of Nebraska, Lincoln.
VILLA, J. 1982. Peces Nicaragüenses de Agua Dulce. p.
253. In: Coleccion Cultural, Banco de America,
Managua.
VIVAS, R.P. and K.R. MCKAY E. 2001. Habitat selection,
feeding ecology and fry survivorship in the
Amphilophus citrinellus species complex in Lake Xiloá,
Nicaragua. Journal of Aquariculture and Aquatic Sci-
ences 9: 32-48.
WAID, R.M., R.L. RAESLY, K.R. MCKAYE and J.K. MCCRARY.
1999. Zoogeografía íctica de lagunas cratéricas de
Nicaragua. Encuentro 51: 65-80.
WILSON, A. B., K. NOACK-KUNNMANN, and A. MEYER. 2000.
Incipient speciation in sympatric Nicaraguan crater
lake cichlid fishes: sexual selection versus ecologi-
cal diversification. Proceedings of the Royal Society Lon-
don B Bio. 267: 2133-2141.
Resumen
Tres especies nuevas en el complejo de especies
Amphilophus citrinellus (Günther) de la laguna de Xiloá
son descritas. Historicamente, muchas formas han sido
documentadas que son fenotípicamente similares a A.
citrinellus, y en las lagunas cratéricas de Nicaragua, este
complejo fue previamente considerado ser representa-
do por una sola, ampliamente variable especie. En la
laguna de Xiloá, las tres especies se aparean asociativa-
mente, y difieren morfológicamente una de otra y de
todas las especies previamente descritas en el comple-
jo A. citrinellus.