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Endlers.nl - Poecilia (acanthophacelus) obscura.. !New species!

A = MALE (P. obscura) B = FEMALE (P. obscura)

Poecilia (Acanthophacelus) obscura or Oropuche guppy, is a new guppy species found in freshwaters of the Oropuche River system, North-eastern Trinidad.. The fish is most related to Common guppy (P. reticulata) and P. wingei (Endler's guppy). P. obscura can cross with Common guppy P. reticulata, which is observed at the laboratoria

Location
The species was found (which was confirmed by DNA sequencing) in the headwaters and upper regions of the northern tributaries to the Oropuche River including the Quare River and La Seiva River. It was also found in the Matura River, the Salybia /Rio Seco Rivers and the L'Ebranche River, which are not tributaries to the Oropuche River but flow independently next north and south into the Atlantic Ocean at the West Coast of Trinidad. The southern and northern boarder of the range of the new species have not been determined exactly, but there are guppies in the Tompire River that flows north of the Matura River and in the Mission River, which flows into the Caribbean Sea. Further west on the northern coastline all the rivers that flow into the Caribbean Sea have no guppies until the Madamas River is reached. This river belongs to the northwestern province, the guppies of which - according to the molecular phylogeny - clearly are P. reticulata. The situation south of the L'Ebranche, wasn't observed jet.

To make clear where they do occur:
P. obscura (OR) Oropuche river (N 10° 43.052'; W 61° 8.871') Road to Cumaca caves, locus typicus
P. obscura (O2) Oropuche, headwaters Laboratory strain "Oropuche 2", established by D. Reznick
P. obscura (RS) Río Seco River Below Río Seco waterfall, at junction with Salybia River
P. obscura (Q6) Quare, below Hollis Reservoir Laboratory strain "Quare 6", established by D. Reznick
P. obscura (Ma) Matura River tributary (N 10° 40.523': W 61° 4.407') 1 km north of road from Sangre Grande to Matura
P. obscura (LE) L'Ebranche tributary (N 10° 30.528'; W 61° 4.204') 3 km south of Upper Manzanilla, road to Plum Milan

Natural Habitat
The Oropuche guppy "P. obscura" was collected from fast flowing small rivers and ditches with generally clear waters. The species also occurs in downstream habitats. Thus it inhabits both so-called low and high predation sites described in the guppy literature (see Magurran, 2005). The locus typicus (Picture below) is a site in the headwaters of the Oropuche River. The river is here about 5 meters wide and fast flowing with a maximum depth of 1 meter. The riverbed is gravel and sand with some larger rocks in the middle. Submerse plants are absent, but the vegetation on the river banks focally reaches into the water and provides shaded sections throughout most of the day.


Researchers noted that on 13-2-2008 (1 p.m., air temperature 25.5°C) the following parameters were recorded: clear water, water temperature 22.5°C, hardness 5-10, conductivity 51 mS, pH 7, nitrate 0, nitrite 0. Accompanying fishes were Rivulus hartii, Astyanax spec., Ancistrus spec. and small cichlids. The inclusion of cichlids and characins defines the habitat as high predation site.

Why is it called, Oropuche guppy "P. obscura"
The name of the new species is derived from the latin word obscurus (hidden) because of its status as a cryptic species. For the common name we propose to call P. obscura the Oropuche guppy due to its main area of distribution.

Body appearance and Colours
Males and females with sex specific coloration (Picture Below, Fig. a,-c). Body color of adult females grayish brown to yellow, fins hyaline. Body sides of adult males with red, blue, orange and yellow bright pigment spots, some reflecting iridescent, usually with 1 to 3 rounded black spots, sometimes with a series of irregularly thin and short or long brown or light black horizontal lines or with very short brown vertical lines sometimes crossing the horizontal bars. The caudal fin base often shows a lower or upper black spot surrounded by small dark and short dashes and yellow pigment, dorsal or ventral caudal fin rays sometimes pigmented and rarely elongated over the caudal margin of the fin, forming a short "sword"; dorsal fin often whitish, dark or polychromatic colored, sometimes flag-like elongated, all other fins hyaline.
Male body coloration extremely polymorphic: in natural habitats no two males being alike.

Oropuche guppy Poecilia obscura from M.K. Meyer, one of the descriptors from this new species:

Together with the "Common" Guppy ( Poecilia reticulata ) and the "Campoma" Guppy ( Poecilia wingei ), the "Oropuche" Guppy ( Poecilia obscura ) represents the subgenus Acanthophacelus Eigenmann, 1907. The "Guppy" is not alone in taxonomy anymore..

See the PDF file below for detail and research results
Description of Poecilia (Acanthophacelus) obscura n. sp., (Teleostei: Poeciliidae), a new guppy species from western Trinidad, with remarks on P. wingei and the status of the "Endler's guppy" (Zootaxa 2266 35-50)