Listrura bernunssa, de Medeiros & Donin & Ferrer & Lima & de Pinna, 2024

Listrura bernunssa , new species urn:lsid:zoobank.org:act:97BDD7D5-661A-4B67-AF21-96AEF999DEA3

( Figs. 1–8; Tab. 3)

Listrura camposi (non-Miranda Ribeiro, 1957). —Nico, de Pinna, 1996:29 (distribution map indicated by “7”, habitat notes). —de Pinna, Wosiacki, 2003:275 (checklist, comparative material examined). —Wosiacki, de Pinna, 2007:74 (checklist, comparative material examined, conservation status).

Listrura sp. —Villa-Verde, 2008:20, 21, 23–42, 43–59, 93, 96, 103 (sampling site, color pattern, external morphology, osteology, character matrix, distribution map indicated by “15”, photographed specimen). —Villa-Verde et al., 2013:61–62 (distribution map, osteological traits).

Listrura sp.1 —Costa, Katz, 2021:318, 319, 338, 341 (molecular phylogeny, distribution map, comparative material examined, character matrix).

Holotype. UFRGS 22874 View Materials , 36.5 mm SL, Brazil, Santa Catarina State, Santa Catarina Island, Florianópolis, Córrego Grande stream at Parque Natural Municipal do Maciço da Costeira , 27°36’37”S 48°30’24”W, 30 May 2017, J. Ferrer, L. Donin, N. Pio & T. P. Carvalho. Tissue sample number: TEC 7338. GoogleMaps

Paratype. MZUSP 63440 View Materials , 1 View Materials , 37.9 mm SL, Brazil, Santa Catarina State, Santa Catarina Island, Florianópolis, Ribeirão da Ilha district , shallow water pool continuous with a mountain stream, ca. 27°42’S 48°32’W, 23 Mar 1993, M. Gomes, O. Peixoto GoogleMaps , R. Schasse & S. Potsch Carvalho e Silva .

Diagnosis. The new species is distinguished from all congeners, except L. camposae , L. urussanga and L. gyrinura , by the number of pectoral-fin rays (three vs. one in L. nematopteryx , L. picinguabae , L. costai , L. macaensis , L. macacuensis and L. menezesi ; two in L. boticario and L. depinnai ; four in L. tetraradiata ). Listrura bernunssa is further distinguished from all congeners with the both anal and dorsal fins, except L. costai and L. urussanga by the position of the dorsal and anal fin relative to the vertebral column: the first pterygiophores of the dorsal and anal fin is located anterior to the neural spine of the 29 th free vertebra (vs. first pterygiophore of the dorsal and anal fin is located anterior to the neural spine of the 30 th free vertebra more). Listrura bernunssa is further distinguished from L. camposae by the absence of a depression at the dorsal margin of the quadrate (vs. presence) and by the absence of a vestigial neural arch at the compound caudal centrum (vs. presence). Listrura bernunssa differs from L. gyrinura by having 47 free vertebrae (vs. 51–52) and six anal fin-rays (vs. eight). Listrura bernunssa differs from L. urussanga by having nine or 10 interopercular odontodes (vs. 6–8) and fewer dorsal (32– 33) and ventral (30–31) procurrent caudal-fin rays (vs. 38–39 and 35–36, respectively).

Description. Morphometric data for holotype and paratype given in Tab. 2. Body elongated, head wider than trunk in dorsal view ( Figs. 1A, D). Cross section of body cylindrical posterior to head, gradually more compressed to anal-fin insertion, tapering to caudal. In lateral view, lowest body depth posterior to head and deepest approximately at origin of dorsal fin. Dorsal body profile almost straight from tip of snout to dorsalfin origin; slightly convex at dorsal-keel (i.e., the skin-fold partly supported by dorsalfin procurrent rays), confluent with caudal-fin. Ventral head profile slightly concave. Ventral body profile convex from gular region to insertion of anal fin; mostly straight from anus to caudal peduncle; concave at ventral-keel (the skin-fold supported by ventral procurrent rays) and confluent with caudal fin. Dorsal keel extending anteriorly beyond dorsal fin as low rayless middorsal cutaneous fold.

Head small, depressed, trapezoid in dorsal view, less deep than body, dorsal surface flat ( Figs. 1B, E). Mouth subterminal, wide; upper jaw slightly longer than lower ( Figs. 1C, F). Anterior margin of upper lip gently convex and continuous laterally with maxillarybarbels base. Lower lip thinner than upper one, nearly straight at anterior margin and continuous laterally with rictal-barbel base. Snout long; anterior profile mostly straight in dorsal view. Anterior nostril small and round, positioned closer to upper lip than to anterior margin of eye, surrounded by short tube of integument continuous postero-laterally with nasal barbel. Posterior nostril round and larger than anterior one; located slightly closer to eye than to anterior nostril, surrounded by low rim of integument. Barbels large; similar to each other in general aspect, their internal cores visible by transparency ( Figs. 1B, E). Maxillary barbel wide at base, gradually tapering to fine distal tip reaching anterior portion of interopercle, and to posterior portion of opercle in paratype. Rictal barbel originating laterally at lower lip reaching to posterior margin of interopercular patch of odontodes in holotype and base of pectoral fin in paratype. Nasal barbel originating at latero-median portion of anterior nostril, wide at base and tapering distally, reaching to posterior region of posterior nostril in holotype and posterior region of opercle in paratype. Eye round, small, located dorsoventrally on head, with well-differentiated lenses and covered with thin transparent integument. Inter-orbital distance nearly four and half times longitudinal size of eye. Opercular odontdophore small, oval, surrounded by fleshy periodontodal fold. Interopercular odontdophore hyaline and ellipsoid, larger compared with opercular one, twice and half times larger than opercular one. Odontodes weakly visible in ventral and lateral views. Branchiostegal membranes narrowly joined to isthmus; six branchiostegal rays visible by transparence in ventral view. Three pleural ribs. Free vertebrae, 47 (40 caudal vertebrae and seven pre-caudal; Fig. 2).

Pectoral-fin rays, three, all rays unbranched and segmented; first ray modified into long filament, approximately 50% longer than the other rays, around half of HL, second and third rays small, approximately two-third and one-third length of first one ( Fig. 1). Axillary gland small, located posterior to pectoral-fin insertion. Dorsal fin small, originating at vertical through 30 th vertebrae, subtriangular, with six unbranched rays, first one not segmented and remaining one segmented (i+5). Anal fin larger than dorsal fin, originating at same line as dorsal fin, subtriangular, with seven unbranched rays, first one not segmented remaining one segmented (i+6). Pelvic fin and girdle absent. Caudal fin elongated, posterior margin round; with 14 principal fin rays (ii+8+iv). Dorsal procurrent caudal-fin rays 32 in holotype and paratype, ventral procurrent caudal-fin rays 30 in holotype and 31 paratype ( Fig. 2).

Mesethmoid narrow just posterior to cornua and widening from posteriorly to that point, its main axis and anterior margin mostly straight, overlain postero-dorsally by frontal ( Figs. 3A, C). Mesethmoid cornua short and straight. Lateral ethmoid with distinctive sub-cylindrical process at posteromedian margin (condition present only on right side of paratype, Fig. 4). Frontal roughly triangular, with small triangular projection at corner. Parieto-supraoccipital roughly pentagonal. Frontal and parieto-supraoccipital sutured; cranial fontanel absent. Sphenotic, pterosphenoid and prootic fused into slender and trapezoid-like complex. Pterotic squarish with laminar lateral process. Epioccipital squarish. Posttemporo-supracleithrum rectangular. Vomer short and ‘bottle-shaped’, with distinct posterior process and lateral constriction on anterior portion ( Fig. 5). Basioccipital fused with exoccipital and with Weberian complex posteriorly.

Premaxilla triangular, with conspicuous protuberance on dorsal surface at posteromedial region, lateral to narrow part of mesethmoid cornua. Two rows of conical premaxilarry teeth: 23 on left and 20 on right side of the holotype, 17 on left and 16 on right side of paratype ( Figs. 3A, B). Maxilla, narrow, elongate, with pointed tips, slightly shorter than premaxilla. Autopalatine squarish; ending postero-laterally in straight small process dorso-medially directed, its mesial margin almost straight its lateral margin with pronounced concavity. Articular autopalatine process conspicuous, with distinctive dorsal process. Lacrimal-antorbital short and club-shaped. Barbular extremely reduced and cylindrical. Dentary triangular, with two rows of small conical teeth, 19 in inner and outer rows on both sides of the holotype, 17 in inner row and 18 in outer row in paratype.

Hyomandibula long with narrow, pointed and elongate anterior process, ventrallycurved at anterodorsal portion, its anterior tip reaching vertical through anterior tip of preopercle ( Figs. 6A, B). Metapterygoid reduced, triangular and articulating by large synchondrosis with anterodorsal portion of quadrate. Quadrate elongate, with narrow laminar process extending anterodorsally from anterior tip; dorsal margin almost straight. Preopercle straight and tapering anteriorly, posterior edge rounded. Interopercle thin,

with nine or 10 side conical odontodes disposed obliquely on posterior portion, arranged in two irregular longitudinal rows. Interopercular anterior process well developed. Opercle slender, with dorsomedial concavity and elongated pointed process dorsally, and bifid process ventrally. Opercle articulating dorsally with hyomandibula via small condyles at anterior process; with seven conic odontodes arranged obliquely in three irregular rows disposed vertically on posterior region.

Parurohyal with small posterior process lateral and arms reaching posterior portion of anterior ceratohyal. Central parurohyal foramen oval ( Figs. 3B, D). Ventral hypohyal trapezoid, with deep fossa on ventral surface for articulation with parurohyal condyle.

Anterior ceratohyal rod-like and constricted at middle. Posterior ceratohyal subtriangular. Cleithrum flat, triangular. Caudal skeleton largely consolidated. Ventral plate formed by fusion of parahypural plus hypurals 1–2; dorsal plate formed by fusion of hypurals 3–5. Dorsal and ventral plates not fused. Uroneural spine elongate, fused to compound centrum but not to dorsal plate ( Figs. 7A, B).

Coloration in alcohol. Dorsum with faint middorsal dark stripe over light brown background originating just posterior to head, narrowing posteriorly to fade at posterior region of caudal peduncle ( Fig. 2). Dorsolateral region of body with two longitudinal dark brown stripes separated by wider stripe gradually paler towards caudal peduncle.

Mid-lateral stripe, with ventral margin, originating immediately dorsal to pectoral fin,

wide anteriorly and narrowing towards caudal peduncle. Ventrolateral region of body pale yellowish with few sparse dark brownish spots, more concentrated between dorsal and anal fins. Myomeres on caudal peduncle outlined by irregular and faint dark marks forming v-shaped pattern. Dorsal and ventral skin-folds in caudal peduncle whitish with sparse dark brown spots at base. Dorsal and lateral parts of head mottled, darkest over supraoccipital, around nares and eyes, and on cheeks. Ventral surface of head pale yellow with light brown blotches, mainly on chin. Pectoral fin hyaline. Dorsal and anal fins hyaline with faint brown markings along bases. Caudal fin with large hexagonal brown spot, and hyaline margin.

Coloration in life. Dorsum and sides of body almost dark brown; abdomen pale light brown, reddish on branchial region due to blood seen by transparency ( Fig. 8). Dorsal and lateral surfaces of head predominantly brown, yellowish areas on ventrolateral region of maxillary barbel and at posterior portion of opercular and interopercular odontodophores, with their bases brownish. Eyes and iris black. All barbels white to hyaline. Dark brown lateral midline along flanks, originating posterior to pectoral fin and vanishing on caudal peduncle, with randomly scattered brownish spots. Pectoral fin hyaline. Dorsal and anal fins hyaline with brown markings at base. Region of procurrent caudal-fin rays hyaline with sparse small dark brown spots concentrated basally. Caudal fin with brownish triangular spot over hypural plate, extending to the middle of principal caudal fin rays.

Geographical distribution. Listrura bernunssa is so far known only from two localities on the Santa Catarina Island, a continental island in Santa Catarina State, Southern Brazil

( Fig. 9). The Córrego Grande stream originates in a dense and preserved fragment of

Atlantic Forest adjacent to the city of Florianópolis. Soon after, the stream runs to the north along the urban area of Florianópolis up to its mouth in the Itacorubi mangrove,

in the western coast of the Santa Catarina island. The second locality is a flooded area in the Ribeirão da Ilha district associated with a stream that drains from a southern mountain chain and runs to the west coast of the Santa Catarina Island.

Ecological notes. Since the 16 th century, the Santa Catarina Island has served as a refuge and point of supply of wood, water and food for expeditionary travelers in the region of the Prata River (Saint-Hilarie, 1978). Four centuries of disorderly occupation on the Santa Catarina Island led to drastic changes on its insular fragment of the AF, with approximately 75% of the original vegetation deforested, and the rest reduced to small fragments in montane areas (Caruso, 1990). Throughout the 20 th century, all lowland areas of the island were occupied (Santiago et al., 2014; IBAM, 2015; Lopes et al., 2020). To mitigate the effects of human occupation, a mosaic of conservation units covering 42% of the island’s total territory were created, preserving small fragments of the AF (Reis, 2010). The freshwater ecosystems of the island of Santa Catarina comprise two lagoons and 15 small river basins (Lopes et al., 2020). The insular freshwater ichthyofauna of the island is composed of 17 species (Bertaco, 2009), including Listrura bernunssa .

The holotype of Listrura bernunssa was collected in a small mountain stream in the “Maciço da Costeira Municipal Natural Park” conservation area, adjacent to the urban area of the city of Florianópolis. The stream has a substantial slope, rocky bottom, clear and swift running waters, and is surrounded by a dense fragment of AF. A single specimen was collected with a handle net in a small shallow pool among rocks by stirring the submerged roots of plants in the left margin. Rains in the region were intense on the collection day and entire preceding week, increasing the water volume in the stream. The following species were caught in the Córrego Grande stream along with L. bernunssa : Ancistrus multispinis (Regan, 1912) ( Loricariidae ), Cambeva barbosae Costa, Feltrin & Katz, 2021 ( Trichomycteridae ), Hollandichthys multifasciatus (Eigenmann & Norris, 1900) ( Characidae ), Phalloceros maldonadoi Souto-Santos, Lucinda & Buckup, 2023 ( Poeciliidae ), and Rhamdia sp. (Hepatpteridae). The paratype locality in Ribeirão da Ilha district was a shallow water pool (no more than 15 cm deep) covered with a dense layer of leaf litter continuous with a swift running rock mountain stream (Sachsse, pers. comm. apud Nico, de Pinna (1996)). On that occasion, the collectors (who are herpetologists) were searching for amphibians. Urban areas and the International Airport of Florianópolis currently circumscribe this locality, which is not protected by any conservation unit.

Etymology. The species epithet bernunssa refers to ‘Bernunça’, a character from the traditional folk manifestation of the coastal region of Santa Catarina. Also known as ‘Boi de Mamão’, it is a legendary creature reminiscent of a dragon, crocodile, or bogeyman, reported for devouring disobedient children. Its origins in Santa Catarina folklore can be traced back to Iberian and Spanish traditions of the Galicia region. A noun in apposition.

Conservation status. Listrura bernunssa is endemic to Brazil and has a restricted geographical distribution, known only from two localities in Florianópolis, with an area of occupation (AOO) of less than 100 km ². The species is rare and not very abundant,

typical of mountain streams with rocky bottoms and clear, fast-moving waters.

The species probably occurred continuously along the island of Santa Catarina, and subpopulations may have been lost locally until the current distribution remained. This region is highly altered, mainly due to the rapid rural and urban expansion on the island of Santa Catarina, characterizing a decline in the quality of the remaining habitat. Due to the dynamics of anthropogenic occupation of the species’ natural environments, and its restriction to preserved environments, the severe fragmentation of the population can be inferred. Therefore, the new species was categorized as Endangered (EN) according to the B2ab(ii,iii) criterion (IUCN, 2022).

Molecular analysis. The BI reconstruction ( Fig. 10) indicates that the closest relative of the new species L. depinnai (PP = 0.99). Interspecific pairwise genetic distances in the cox1 gene are 2.9% with L. depinnai , 3.4% with L. boticario , 6.1% with L. camposae , 16%

with L. costai , 17% with L. nematopteryx , L. macacuensis , L. macaensis , L. picinguabae and

L. tetraradiata ; and 18% with for L. menezesi ( Tab. 4).