Rhadinoloricaria andaki, Provenzano-Rizzi & Chaves-Moreno & Ordoñez & Ortega-Lara, 2024

Provenzano-Rizzi, Francisco, Chaves-Moreno, Luis Carlos, Ordoñez, Betselene Murcia & Ortega-Lara, Armando, 2024, A new species of Rhadinoloricaria (Siluriformes: Loricariinae) from Colombia, Zootaxa 5474 (2), pp. 127-138 : 128-135

Rhadinoloricaria andaki new species urn:lsid:zoobank.org:pub:34278FBD-42E6-4A1B-8B80-C54A6156667A

Figs. 1 , 2 , 3 ; Table 1

Holotype. CZUT-IC- 13897, 156.1 mm SL, Colombia, Departamento Caquetá, Municipio Montañitas, Amazonas River Basin , Caquetá River system , San Pedro River tributary of Orteguaza River , near Santuario village , approx. 01°30’02.3”N 75°28’26.3”W, 230 masl, 26 October 2022, D. Vélez

Paratypes. CHIFF-0219, 9, 119.1–155.0 mm SL, same data as holotype.

Non type specimens: These specimens were excluded from type series because are not well fixed, don’t show the genus buccal character, and to avoid future taxonomic confusion. Colombia: MBUCV-V-35721 , 2, 128.3– 128.9 mm SL, Colombia, Quebrada La Yuca tributary of Hacha River , near Florencia , 250 masl, August 2008 - September 2009, M. Peláez and party. MBUCV-V-35773 ; 117.5 mm SL, C&S; Quebrada La Yuca tributary of Hacha River , near Florencia , 250 masl, October 2008, L. C. Chaves. Ecuador: MEPN-I 14710 , 3, 107.4– 118.7 mm SL; Corrientes River , approx. 02°10’50”S 76°40’32”W, May 1964, M. Olalla .

Diagnosis. Rhadinoloricaria andaki is distinguished from all congeners, except R. macromystax and R. stewarti by its projected snout, depressed and spatula-shaped vs. snout slightly or not projected and not spatula-shaped ( Provenzano-Rizzi & Barriga-Salazar 2020, Figs 7, 8). It is further distinguished from all congeners, except R. macromystax , R. rhami and R. stewarti , by buccal ornamentation on the palate, just behind premaxillaries at midline, with one thick, elongate barbelet that branches into three or four conical, unbranched, similarly-sized arms vs. one barbelet, which ramifies into three or four conical, unbranched arms, but the most anterior arm is much longer than the rest in R. bahuaja , or with six or seven elongated, branched and unbranched barbelets in R. condei , R. laani and R. ommation ( Provenzano-Rizzi & Barriga-Salazar 2020, Fig. 7, 8). It differs further from R. rhami , by its maxillary barbel length, extending beyond pectoral-fin base vs. maxillary barbel not surpassing gill opening. It differs from R. bahuaja by having lateral external region of each premaxilla without elongated, conical and unbranched barbelet vs. lateral external region of each premaxilla with one elongated, conical and unbranched barbelet ( Provenzano-Rizzi & Barriga-Salazar 2020, Fig. 7). It differs from R. macromystax , R. rhami and R. stewarti by pattern of plates on abdomen which is only partially covered with only a midline series with one or two irregularly-shaped plates, loosely or well-articulated, extending from pectoral girdle to anterior to pelvic-fin origin, leaving well-defined naked areas at sides vs. abdomen completely covered in R. macromystax and R. rhami or if partially covered, the plates never disposed as described above and without the two well-defined naked areas in R. stewarti ( Provenzano-Rizzi & Barriga-Salazar 2020, Figs. 7). In addition, R. andaki is distinguished from R. macromystax y R. stewarti by having a greater postdorsal length 64.4–67.3% SL vs. 54.3% SL and 57.5%–59.0% SL, respectively; and is distinguished from R. macromystax by having a shorter snout length 11.5%–13.5% SL vs. 14.6%–15.1% SL and a longer postanal length 46.8–50.3% SL vs. 45.2%–46.1% SL.

Description. Morphometric data given in Table 1 . Head and body very depressed, principally caudal peduncle. Adipose fin absent. Dorsal profile of body from tip of snout to anterior border of eyes straight and ascendant, then gradually descending straight to caudal-fin origin. Ventral profile of body straight. In dorsal view, body contour posterior to dorsal-fin origin straight and convergent, tapering gradually. Dorsal surface from dorsal-fin origin to caudal-fin origin flat. Ventral surface of caudal peduncle flat ( Fig. 1 ).

Head contour, in dorsal view, triangular with spatula-shaped, projected snout, wide, anterior edge rounded and sides straight ( Fig. 1 ). Nares very near eye, and juxtaposed, anterior smaller than posterior. Interorbital width narrow. Orbit with posterior notch. Anterior border of orbit raised and with small odontodes. Two low keels run convergent from posterior border of orbits to half supraoccipital and then become parallel on posterior supraoccipital and two first pre-dorsal plates and continues as single low keel on third pre-dorsal plate. In ventral view of head, tip of snout covered with plates and posteriorly naked, in front of the upper lip. Surface under lower lip and anterior to pectoral-fin girdle naked ( Fig. 2 ).

Abdomen partially covered. Pectoral girdle covered by transverse band of irregularly arranged plates with different shapes and sizes. Behind pectoral girdle at belly midline, longitudinal series of plates extends towards anus. That series has one or two similarly sized and irregularly shaped polygonal plates. Before pelvic girdle level, plate series becomes wider, with more different sized polygonal plates, ending just in front of anus. Longitudinal medial row divides abdomen surface into two well-defined naked areas ( Figs. 1 , 2 ). Laterally, at pectoral-fin bases there is a longitudinal plate series with seven to nine more or less rounded plates. Eight to eleven thoracic plates, first two to five not projected laterally, remaining plates more elongated, projected laterally ( Figs 1 , 2 ).

Mouth ventral, with more or less trapezoidal contour. Upper lip narrow, its border with some unbranched and one or two branched barbelets; upper lip surface with few barbelets and very few or no papillae. Upper lip border continuous with maxillary barbel. Maxillary barbel very long, surpassing pectoral-fin base, almost reaching pelvic-fin origin. Maxillary barbel has both branched and unbranched barbelets along its border. Lower lip broader than upper, its border has longer branched barbelets. Lower lip surface covered with barbelets or with papillae and barbelets ( Fig. 3 ). Presence of papillae on lower lip may be correlated with a male sexual dimorphism during the breeding season (males carry the eggs in the mouth). Teeth few, similar in both jaws. Teeth small or very small, spoon shaped, with a small lateral projection not reach distal margin, cusp rounded. Premaxilla with five teeth. Dentary with nine or ten teeth ( Fig. 3 ). Buccal ornamentation composed of outer side of premaxillae with one or two conical branched barbelets and on palate midline behind premaxillaries one thick barbelet, branched in three or four unbranched, conical, similarly-sized arms ( Fig. 3 ).

Lateral body plates 32–33. First three to four lateral plates, posterior to cleithral spine, without keels, then 14–15 lateral plates with dorsal and ventral keels that gradually converge posteriorly and join in a single central keel; next 15–16 single keeled lateral plates, continues to base of caudal fin ( Fig 1 ). Dorsal-fin i,7 its origin located slightly behind pelvic-fin origin. Origins of dorsal and pelvic fins at lateral plate six. Pectoral-fin i,6, when adpressed tip of unbranched ray surpassing pelvic-fin origin. Pelvic-fin i,5, distal region of the unbranched ray is slightly curved, adpressed almost or reaches anal-fin origin. Anal-fin i,5, its origin on lateral plate 11. Caudal-fin i,10,i, dorsal, unbranched caudal ray projected as long filament ( Fig. 1 ).

Coloration in alcohol. Specimens preserved in 70% alcohol have dorsal surface of head and body yellow or light brown with irregular and narrow black stripes (vermicular pattern) ( Fig. 1 ). Ventral region of head and body whitish ( Fig. 1 ). Dorsal, pectoral and pelvic fins with rectangular or square black blotches on rays; interradial membranes hyaline. Dorsal-fin spine with eight to ten black blotches, pectoral-fin spine with six to eight, and pelvic-fin spine with four to six. Anal-fin uniform whitish or yellow. Caudal-fin with four black blotches on rays, and two transverse black bands. Anterior transverse band wide and well defined near base of middle rays; posterior band thin and weakly defined. Distal border of caudal-fin hyaline.

Coloration in life. Recently captured specimens have the vermicular color pattern described previously. On ventral side of body, unplated areas of the belly white and plated areas golden brown ( Fig. 4 ).

Geographic distribution. The known geographic distribution of the new species includes two remote aquatic systems both tributaries of the Amazon River. The specimens from Colombia were captured from the San Pedro River, a tributary of the Orteguaza River and the Quebrada La Yuca a tributary of Hacha River; rivers that are tributaries of the Caquetá River system (called Japurá River in Brazil), Amazon River basin. In Ecuador, specimens come from the Corrientes River, which flows into the Tigre River, Amazon River basin ( Fig 5 ).

Ecological notes. At the type locality, the San Pedro River has 230 masl. The river originates in the Cordillera Oriental de Los Andes and flows to the Orteguaza River. At this point, is a whitewater river which may become a clearwater river during the summer when amount of suspended sediment diminish. The bottom is composed by sand, rocks and gravel. Also at this level the river is not polluted. Rhadinoloricaria andaki is found at depths between 50 and 200 cm and is associated with fine sand beaches ( Fig 6 ). Apparently, the species lives buried during daylight hours, and the specimens were captured at night when it appears to be active.

The Quebrada La Yuca originates at 1,350 masl in the Cordillera Oriental de Los Andes, Reserva Forestal de la Amazonia. The length of the creek is 20,739 meters and its watershed area is 5,753 hectares, which represents 11.74% of the Hacha River Basin. The shores are composed by secondary and tertiary forests, grasslands and dual purpose cattle farms. The topography of the collection site is flat with some hills, and slopes can reach 15°. In the area, there are fast flowing zones, stretches with medium flow and pools with slow flow. The bottom is composed of sand, rocks and gravel. The flow velocity is about 5 m /s. The greatest width is 19 m and the depth fluctuates between 15 and 60 cm, but in some places the depth exceeds 2 m. Some physical and chemical characteristics taken at the capture site were: dissolved oxygen 7.37, pH 6.84 and temperature 23.9° C. The conservation status of the creek can be described as marginal by the impact of human activities.

As the Hacha River passes through the city of Florencia (Caquetá, Colombia) and is negatively impacted by different human activities such as: car and clothes washing, gravel and sand removal, urban wastewater, agriculture and farming. Despite this, capture of some species of fishes downstream of the city seems to indicate that pollution levels do not reach extreme values and allow the survival or movement of some species.

Etymology. The species name honors the Andakí or Andaquí indigenous people; ethnic group of South America whose territory included the upper Caquetá River basin. A noun in apposition.

Conservation status. Unknown.

Remarks. Rhadinoloricaria andaki is captured as an ornamental fish and has high monetary value compared with other ornamental fish species caught in the surroundings areas of Florencia city. Prices ranges 3,000 to 15,000 COP (approx. 0.80 to 2.50 US $) per specimen before sent to warehouses in Bogotá and extraction volumes are on the order of 235 specimens per year in average (SEPEC-AUNAP 2023). This quantity of specimens does not seem to be elevated, but because no values of abundance in capture localities are known, the conservation status of the species is speculative.

Figures

FIGURE 1. Rhadinoloricaria andaki, CZUT-IC-13897, holotype, 156.1 mm SL. Lateral, dorsal and ventral views. Scale bar = 10 mm. Photo by: Armando Ortega-Lara.

FIGURE 2. Rhadinoloricaria andaki, CZUT-IC-13897, holotype, 156.1 mm SL. a) Head ventral view, mouth and lips details. Scale bar = 5 mm. b) Close–up of palate ornamentation and teeth. Scale bar = 2 mm. Photos by: Armando Ortega-Lara.

FIGURE 3. Comparative ventral views, head contour, snout projection and abdominal cover. a) R. macromystax MEPN-I 18664, 114.4 mm SL. Photo by: F. Provenzano, b) R. stewarti MEPN-I 10303, paratype, 125.4 mm SL, Photo by: F. Provenzano and c) R. andaki, CZUT-IC-13897, holotype, 156.1 mm SL. Photo by: Armando Ortega-Lara.

FIGURE 4. Live color pattern, CZUT-IC-13897, holotype, 156.1 mm SL. Photo by Armando Ortega-Lara.

FIGURE 5. Map of Colombia showing the geographic records of Rhadinoloricaria andaki type locality (red star).

FIGURE 6. Photo of the San Pedro River with sand bank at shore also forming an island; habitat where specimens of R. andaki are captured, more frequently. Photo by; Deiber Vélez.