A new species of Laetacara from the northern Brazil coastal floodplains ( Teleostei : Cichlidae )

Laetacara flamannellus sp. n. is described from the northern Brazilian coastal floodplains. It differs from all its congeners by a combination of character states: presence of a dark brown or black spot located on dorsal-fin base; presence of a yellow stripe on the middle portion of the dorsal fin, crossing the whole fin; presence of an orange ring around the dorsal-fin base spot; absence of a red pigmentation on belly; absence of a red or purple zone on the anal-fin base; absence of a red zone on the caudal-fin base; cycloid scales on the opercle plate; and trunk scales above upper lateral line with few ctenii. The presence of a deep notch in the dorsal margin of the anterior ceratohyal, often used as diagnostic for Laetacara, is confirmed here for L. flamannellus.

Laetacara is included in the tribe Cichlasomatini (Kullander, 1998;musilOvá et al., 2008;and smith et al. 2008), subfamily Cichlinae (sparKs &smtih, 2004 andsmith et al. 2008), and has been considered as closely related to Nannacara regan, 1905 and Cleithracara Kullander & nijssen, 1989(Kullander, 1998and smith et al. 2008).According to Kullander (1986), Laetacara is diagnosed by a combination of: a deep notch in the dorsal margin of the anterior ceratohyal (Kullander, 1986;fig. 149 and OttOni et al. 2009;fig. 4), a character state only shared with Cleithracara among cichlid genera; preopercle with two scales on the horizontal and one (rarely two) on the vertical limb; two scales rows on cheek; and absence of posterior lateral ethmoid-palatine articulation and accessory caudal-fin lateral line.Later OttOni &cOsta (2009) andOttOni et al. (2009) confirmed the presence of a deep notch on the dorsal margin of the anterior ceratohyal for L. dorsigera, L. curviceps and L. araguaiae.However, neither casciOtta (1998) for some populations of L. dorsigera in Argentina, nor staecK & schindler (2007) for L. fulvipinnis observed the presence of that notch.
A new species of Laetacara is herein described from the northern Brazil coastal floodplains, more specifically in isolated basins of the Amapá state, north of the rio Amazonas basin.The eastern plains of Amapá state is a complex mosaic of dry and flooded environments (tOledO & Bush, 2008).The flooded environments, representing about 10 % of the state area, have characteristic vegetation consisting of flooded forests and flooded grasslands (pereira et al., 2002).Those environments are subject to seasonal variation caused by rain and wind annual regimes (chellappa et al., 2005).In the dry season, from July to December, the water is restricted to the main river channel but during the rainy season, from January to June, the river overflows from its main channel (pereira et al., 2002).Particularly in the flooded grasslands, during the rainy season as the river overflows many temporary lakes regionally known as "ressacas" are formed.This environment is peculiar because during the rise in the water level it is oxygen and nutrient enriched, favoring a rapid planktonic and vegetation growth, making it an ideal site for small fish breeding and feeding (gama & halBOth, 2003).

Material and Methods
Material is deposited in IEPA, Instituto de Pesquisas Científicas e Tecnológicas do Amapá, Macapá; MNRJ, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro; and UFRJ, Instituto de Biologia, Universidade Fe de ral do Rio de Janeiro, Rio de Janeiro, Brazil.
Measurements and counts are made according to OttOni et al. (2011), with addition of: number of teeth on the posterior margin of the ceratobranchial 5 and number of teeth on the transversal series of ceratobran chial 5 (Kullander, 1986); scale counts of the oper cular plates and prepelvic scales series are made ac cording Kullander (1983); and predorsal scales series (squ.Predorsal), a longitudinal count of scales, on a dorsal view, from the first dorsal-fin spine to the last scale on the dorsal profile.Precaudal vertebrae is equi valent to abdominal vertebrae sensu Kullander (1983;1986).In description and table 2, the number of specimens exhibiting a character state is presented in paren theses.
Measurements are presented as percentages of standard length (SL), except for those related to head morphology, which are expressed as percentages of head length (HL).Measurements were taken on the left side of each specimen with digital calipers under a binocular microscope.Osteological studies were made on cleared and counterstained (C&S) specimens pre pared according to taylOr & van dyKe (1985), and the osteological nomenclature follows cOsta (2006).Nomenclature related to colour pattern follows Kul lander (1983).The lateral band sensu Kul lan der (1983) is here nominated longitudinal stripe.Colouration in life was observed in about 20 live specimens during field work, which five of them were photographed.
For species delimitation we adopted the population aggregation analysis (davis & nixOn, 1992), a character-based method in which species are delimited by a unique combination of stable morphological character states occurring in one or more populations.Diagnosis.Laetacara flamannellus sp.n. differs from all its congeners, except L. curviceps and L. dorsigera, by having a dark brown or black spot located on the dorsal-fin base, above trunk bar 5 (vs.spot absent); from L. curviceps and L. dorsigera by the presence of an orange flame ring around the dorsal-fin base spot (Fig. 1 B) ( vs .orange ring absent); from L. dorsigera by the absence of a con-spicuous red belly in breeding specimens (vs.breeding males and females with conspicuous red cheeks, gill covers and belly); and from L. curviceps by the presence of a yellow stripe on the middle portion of the dorsal fin, along the whole Laetacara flamannellus, new species (Figs.1a -b)    Trunk and caudal peduncle covered with strongly ctenoid scales, but scales above upper lateral line with few ctenii.Predorsal scales cycloids with a trisserial scaly pattern.No scales between dorsal and anal-fin rays, and caudal fin with few ctenoid scales on base (absent in some specimens).Pectoral and pelvic fins without scales.Two scales between lateral lines, upper and lower lateral lines scales not overlapping vertically.Opercular plate scales cycloid.Three vertical rows of scales on opercle plate, two horizontal rows on cheek, and one row on subopercle, interopercle and preopercle.

Description. Morphometric data are summarized in
Ceratobranchials 1 -4 without tooth plates.Ce rato branchial 5 partly medially sutured and relatively robust, with 6 (1), 7 (3) or 8 (1) teeth along midline and 20 (1), 21 (2), 22 (1) or 23 (1) teeth along posterior margin.Posterior teeth usually more compressed.Posterior and medial teeth larger than lateral and anterior teeth.Posterior teeth bicuspid, curved forward.Side of head with colouration as side of body, with blue or green iridescence on opercle.Two blue stripes below eye.Some blue marks on opercle, sometimes blue mark on snout.Snout yellow, upper jaw darker than lower.Iris with yellow or orange colouration.
Dorsal fin with blue background and intense yellow stripe crossing middle of fin, from first spine to distal tip of fin.Some transversal intense yellow bars located on soft portion of dorsal fin (rays regions), alternated by metallic blue dots.Dorsal-fin margin with orange

A B C
Laetacara flamannellus sp.n. is similar to L. curviceps in general counts and morphology, and similar to both L. dorsigera and L. curviceps in general colour pattern of preserved specimens.These three species differ from all their congeners by sharing a characteristic colour pattern: the presence of a dark brown or black spot on the dorsal-fin base, above trunk bar 5 (vs.absence).With the addition of the new species herein described, Laetacara currently comprises seven valid species, being the ninth more speciose genus of Cichlinae.
OttOni et al. (2009) did not find ctenii on the opercular plate scales of L. curviceps, but re-examination of specimens of that species, including newly collected material, listed on the material, demonstrated that few ctenii are present on the opercular plate scales.
Comparing the shape of the caudal-fin base spot among congeners, some differences can be observed: Lae ta cara flamannellus sp.n. and L. curviceps possess two patterns of caudal-fin base spot: spot divided in two ellip tical bands or divided in two bands very elongated (see Fig. 3A -B) (the colour pattern of the caudal-fin base spot is detailed in the description of colour in alcohol above); L. dorsigera possesses only one pattern: spot divided in two elliptical bands (see Fig. 3A); L. ara gua iae usually possesses usually spot not divided in two bands (Fig. 3C), with just few specimens possessing the spot divided in two elliptical bands (Fig. 3A); and L. thayeri does not possess any spot.No specimens of L. fla vi la bris and L. fulvipinnis were examined, impos si bi li ting any conclusion about the pattern of the caudal-fin base spot in these two species.prevailed (see Fig. 5).This flooded grassland appears only during the rainy season, from January to June, as a consequence of river overflows.The annual air mean temperature is 28 °C (pereira et al., 2002).In the same biotope, we found Rivulus schuncki cOsta & de luca, 2011, juveniles of Hoplerythrinus unitaeniatus (spix & agassiz, 1829) and Nannostomus sp.
Etymology.The name flamannellus is a contraction from the Latin flammeus, meaning flame coloured, and from the Latin annellus, meaning ring, due to the presence of an orange flame ring around the dorsal-fin spot, one of the diagnostic character states of the new species.

Discussion
Laetacara flamannellus sp.n. is herein described from the coastal river floodplains of eastern Amapá, northern Brazil.It is included in Laetacara because it fits with all the diagnostic character states proposed by Kullander (1986) for the genus, as cited above.

Vertebrate
Zoology n 62 (2) 2012 Large laterally compressed teeth bicuspid.Presence of two supraneurals and one narrow ectopterygoid.Colouration in alcohol.(Fig. 1A) Side of body light brown with seven dark brown bars between posterior limit of caudal peduncle and posterior margin of opercle.Trunk bars usually forked.Two dark spots; first spot divided in two bands, one larger and one smaller, located on base of caudal fin through lower lateral line, with two distinct patterns: bands elliptical, more common in juveniles (see Fig. 3A), and bands very elongated, like a bar (about 80 % of the specimens, mainly in the adults) (see Fig. 3B); second spot squared, located on junction between longitudinal stripe and vertical trunk bar 5. Interrupted longitudinal stripe brown between trunk bar 1 and margin of opercle, lighter and inconspicuous between bars, and darker anteriorly to trunk spot.Side of head with ground colouration as trunk, darker on opercle.Dorsal fin with one black or dark brown spot located on its base, above trunk bar 5, and one spot above trunk bar 4 in some specimens.Dorsal and anal fins light brown, with small interrupted bars on posterior portion of fins, located anteriorly to trunk bar 2. Caudal fin hyaline, with small interrupted bars on whole fin.Pectoral fin hyaline, pelvic fin dark brown.fin, in some specimens surpassing posterior margin of caudal fin.Caudal fin rounded.Pectoral fin rounded.Pectoral-fin base on vertical through dorsal-fin origin.Tip of pectoral-fin reaching vertical through vertical trunk bar 4. Pelvic fin pointed.Pelvic-fin base on vertical through second or third spine of dorsal fin.Tip of pelvic fin approximately reaching vertical through second anal-fin ray.

Fig. 4 .
Fig. 4. Distribution map of L. flamannellus sp.n.. Triangle represents the collecting site of the holotype, and circles of paratypes.

Fig. 3 .
Fig. 3. Caudal-fin base spot of: A -some juveniles of L. curviceps and L. flamannellus sp.n., few specimens of L. araguaiae and specimens of L. dorsigera; B -80 % of the specimens (mainly adults), of L. curviceps and L. flamannellus sp.n.; and C -majority of the specimens of L. araguaiae.

Fig. 5 .
Fig. 5. Photograph of the collecting site of the holotype.Photograph from Beatriz Camisão.

Table 1 ,
meristic data in Table2.Dorsal profile slightly convex from snout to caudal-peduncle origin, leaner