A NEW SPECIES PREVIOUSLY CONFUSED WITH CAECILIA PACHYNEMA (GÜNTHER, 1859) (AMPHIBIA: GYMNOPHIONA: CAECILIIDAE) FROM THE CORDILLERA CENTRAL OF COLOMBIA UNA NUEVA ESPECIE PREVIAMENTE CONFUNDIDA CON CAECILIA PACHYNEMA (GÜNTHER, 1859) (AMPHIBIA: GYMNOPHIONA: CAECILIIDAE) DE LA CORDILLERA CENTRAL DE COLOMBIA

— Caecilia pachynema is a distinctively colored species known from western Ecuador and supposedly from a remote population in the northern Cordillera Central of Colombia. Previously it had been detected that the Colombian populations of "C. pachynema’’ were likely an undescribed species. Material gathered over the past twenty years allows us to describe this new species and restrict the known distribution of C. pachynema to Ecuador.


INTRODUCTION
Caecilia pachynema (Günther, 1859) is a large, stout caecilian with large, recurved dentary teeth, known from western Ecuador in the provinces of Azuay, El Oro, Intac, Pallatanga, and Pichincha. This species bears a particular color pattern of white rectangles on the annuli, subdivided by dark grooves, constituting a broad ''ventrolateral stripe'' along the body. Taylor (1968) remarked that this species inhabited the Pacific drainages of Ecuador, the Caribbean drainages of Colombia, and considered that it might extend into Peru. Our results indicate this species is restricted to western Ecuador as it has not been found in the neighboring Pacific lowlands of Colombia. Furthermore, the Peruvian record was subsequently designated as the holotype of C. inca by Taylor (1973).
The presence of C. pachynema in Colombia was first reported by Dunn (1942), who provided a brief taxonomic account but had a mixed series that comprised more than a single species. Later, Taylor (1968Taylor ( , 1973 named C. attenuata Taylor, 1968, C. crassisquama Taylor, 1968, and C. tenuissima Taylor, 1973, which were taken from the type series of Dunn's C. pachynema. Lynch (2000) Fernández-Roldán & Lynch -A new Caecilia from Colombia detected an undescribed species misidentified as 'C. pachynema' known from around Medellín, Antioquia, Colombia, and attributed the taxonomic confusion to the recurrent presence of similar coloration patterns (like that of C. pachynema) in various Colombian species of Caecilia (i.e. C. occidentalis Taylor, 1968 and C. sp.) but deferred from describing it until further material became available. Over the past twenty years, enough material has become available for a robust taxonomic assessment of this new species and its intraspecific variation.

MATERIALS AND METHODS
All groove counts were performed under a stereoscope and repeated at least twice for each individual. Entomological pins were used to demarcate and differentiate primary and secondary grooves in order to avoid misrepresenting their individual counts. Careful incisions to the mouth's commissure were performed using a razor blade in order to fully open the mouth and access dentition, choanae, and tongue when necessary. A sharp pin was used to open the pockets where the primary grooves concealed their dermal scales. Once these were obtained, they were described in shape and size and put back in their respective positions so no material would be lost or damaged. Subdermal scales were searched by partial dissection of the annuli close to mid-body point and removing a section of epidermis to expose the connective tissue and determine their presence or absence.
Sex was determined through direct examination of gonads by performing a ventral longitudinal incision posterior to the midbody point and anterior to the vent to look for testis in males and ovaries in females; if mature testis or ovaries were found, these were considered to be adults. Juveniles are much smaller than adults, have undefined collars, and bear an incomplete dentition. Diagnosis and description follow Taylor (1968) and Maciel & Hoogmoed (2018) with some modifications. All measurements were performed under a Zeiss stereoscope; these were taken to the nearest 0.1 mm using a Neiko digital caliper with the exception of total length, which was determined using a measuring tape.

Caecilia antioquiaensis
Caecilia abitaguae (137-148 primaries and 0-5 secondaries), C. subterminalis Taylor, 1968 (170 primaries and 16 secondaries), and C. tenuissima (186 primaries and 10 secondaries) have overlapping counts of primary grooves but many fewer secondary grooves or none at all. Caecilia flavopunctata Roze & Solano, 1963 (155 primaries and 27 secondaries) has overlapping counts of grooves but its characteristic "funnel-shaped", truncated head (Taylor, 1968: 382: Fig. 199 B-D) differs from that of C. goweri, which is rounded. Caecilia nigricans Boulenger, 1902 also has overlapping counts of primary grooves (157-189) but higher counts of secondary grooves (32-62) furthermore, C. nigricans entirely  The new species most closely resembles C. pachynema and C. occidentalis, mainly because these Caecilia are very elongate, bear subdermal scales within the connective tissue of the skin, have few (or no) secondary grooves, and bear a series of light colored ventrolateral rectangles subdivided by the primary grooves throughout their body lengths. Discerning C. goweri from C. pachynema could be difficult given that both species have overlapping counts of teeth on all four series, overlapping counts lacks an unsegmented terminal shield (Taylor, 1968;409), unlike the new species. Caecilia subnigricans Dunn, 1942 has overlapping counts of grooves (151-161 primaries and 17-31 secondaries) but it differs from the new species in the shape of its dermal scales, which are thin and mostly rounded in C. goweri, but thick and straight at the margin of inception with the scale pocket but with a rounded terminal margin in C. subnigricans (Taylor, 1972: 1118).   Fernández-Roldán & Lynch -A new Caecilia from Colombia of primary grooves and a similar color pattern. Still, C. pachynema tends to have a lower count of primary grooves (150-163) and its teeth are much more recurved than those of C. goweri (Taylor, 1968: 428: Fig. 228 C). Dermal scales are present in both species (contra Taylor, 1968) and these tend to be subrectangular in C. pachynema (Taylor, 1973(Taylor, : 1113 Fig. 68) but clearly rounded in the new species. Some individuals of C. pachynema lack secondary grooves entirely but others have up to 11 secondaries; in contrast, all individuals of C. goweri bear secondary grooves (7-20). The last primary and secondary grooves dorsally encompass the terminal portion of C. goweri but these do not extend onto the ventral surfaces of the terminus, hence it has a small terminal shield, while C. pachynema bears a large, notable, completely unsegmented terminal shield (Taylor, 1968: 428: Fig. 228 D-E) (Fig. 4).
To a certain degree, C. occidentalis is easier to discern from C. goweri because C. occidentalis has an even higher count of primary grooves (191-221) (Taylor, 1969) and because the nuchal collars of C. occidentalis are not clearly demarked as those of C. goweri; in C. occidentalis the third nuchal groove is complete (Taylor, 1969: 787: Fig. 1) while it is only complete ventrally in the new species. Dermal scales of C. occidentalis seemingly vary in shape from subtriangular, to subrectangular to oval sensu Taylor (1972: 1022) but these are circular in C. goweri. The new species has larger premaxillary-maxillary teeth than C. occidentalis, their dentary teeth are slightly recurved and of very similar proportions in both species, however these are well spaced from each other in C. goweri but set closer together in C. occidentalis, where the first 3-3 are set further from each other and the posterior 5-5 are closer together.
Snout rounded in dorsal and ventral view but blunt in profile; it projects 2.5 mm beyond the mouth. Nostrils clearly visible in dorsal view and in profile but not visible in ventral view; these are circular in shape and much closer to the tentacular opening than to eye. Distance between nostril and tentacular opening 1.9 mm, that between nostril and eye 3.8 mm. Eyes small, 0.6 mm in diameter, partially concealed by very translucent epidermis and resemble white dots. Distance between eye and commissure of mouth 3.8 mm. Interorbital distance 5.3 mm and the distance between snout tip and eye 4.9 mm. Tentacular openings oval in outline, elevated above skin, positioned below and slightly posterior to nostril, equidistant to margin of mouth and nostril; not visible in dorsal view but prominent in ventral and lateral views. First nuchal collar smaller than second; both nuchal collars bear a very faint nuchal groove dorsally and ventrally; third nuchal groove is complete ventrally but incomplete dorsally. Width of body increasing past the nuchal collars onto the fourth fifth of the total body length, it then tappers slightly only to become stouter onto the final fifth of the total body length, the terminus is stouter than the width of the head. Primary grooves 168, mostly incomplete, only the last 14 completely encircle the body near the terminus; secondary grooves 14, these are short and barely extend onto the ventral surfaces. Vent transverse, of moderate size, of same color as surrounding skin, bearing small denticulations, 4 anteriorly and 5 posteriorly, seemingly no anal glands on the anterior margin of the vent, but phallodeum was badly extruded and this could have hidden them.
A small, unsegmented terminal shield, given that it is dorsally interrupted by the last short primary and secondary grooves even though these do not extend onto the ventral surfaces of the terminus. Dermal scales first appear at the first primary groove, where they are small, slightly oval, and folded upon (misshapen) but those found towards the terminus are circular and slightly thicker at the insertion margin; these are present up to the last primary groove. Dermal scales closer to the venter are larger in size. Many subdermal scales are found in the connective tissue of the skin. All teeth are thin, monocuspid, pointed, and slightly recurved; those on the premaxillary-maxillary and prevomeropalatine series are smaller in overall size than those on the dentary series; splenial teeth are of moderate size and not concealed by the tongue or gums. The premaxillary-maxillary bears 4-1-4 teeth that are well spaced and large but decreasing in size posteriorly; the prevomeropalatine series has 5-5 teeth, which also decrease their overall size posteriorly; the dentary has 5-6 teeth on each side and splenials are 3-2, straight and pointed. Teeth in dentary series more recurved than those on premaxillary-maxillary and prevomeropalatine series. Choanae oval transversally in shape, the maximum diameter of one choana is 0.6 mm, and the space separating them is 1.3 mm, tongue with protruding narial plugs, which are darker than the coloration of the tongue. Teeth replacement is evident in the gums.

Coloration in preservative.
Coloration in life is unknown. In preservative, coloration is bright gray dorsally, followed by a cream median ''lateral stripe'', which extends along the total body length, more evident anteriorly than posteriorly, ventrally same color as dorsum but paler. The color of the terminus is bright cream against the dull cream color of the ventrolateral rectangles ( Fig. 1A-D).

Fernández-Roldán & Lynch -A new Caecilia from Colombia
Variation. There is slight variation in the color pattern because the ventrolateral rectangles are more prominent in some individuals (such as the holotype) than in others such as MHUA 8115 (Fig.  2). In some individuals such as the holotype (MHUA 3241) (Fig.  1C) and paratype MHUA 8115 (Fig. 2) the eyes are concealed by translucent epidermis to a higher degree than in others, such as MHUA 3915 and MHUA 6296. Dermal scales can be rounded (as in MHUA 3241,3915,6296 and 8115) or very slightly more oval . Juveniles ) are very small (115-180 mm total length), have undefined nuchal collars, and bear an incomplete dentition with only 2 premaxillary-maxillary teeth and no dentary teeth although traces of emerging teeth can be seen within the gums. Adult males of C. goweri tend to have the eye located equidistant between the commissure of the mouth and the nostril, while adult females tend to have the eye located closer to the commissure of the mouth than to the nostril, suggesting sexual dimorphism (Table 1).
Etymology. We name this species after Dr. David J. Gower, merit researcher at the Natural History Museum in London, U.K., for all his contributions to the anatomy, evolution, systematics, and taxonomy of caecilians and snakes.

Remarks.
Coloration in life is unknown for the holotype of C. goweri, but paratype MHUA 8115 is mostly dark gray or slate along the dorsal surfaces of the body, paler gray or slate on the flanks with purple hues and pale cream ventrally, which appears even paler (close to white) on the last 30 primary grooves and the terminus; head, tentacles, lips and nostrils are salmon pink surrounded by shades of dark blueish gray (Figs. 2-3). Taylor (1968: 431) paid close attention to the color pattern of C. pachynema  and described it as "Ventrolaterally there is a brownish cream stripe ranging from the first collar to very near vent-level but broken by dark lines in the grooves, leaving quadrangular marks on each annulus. A median ventral stripe of grayish-slate, lighter than the dorsum'' (Fig. 4). We consider that neither C. goweri nor C. pachynema bears a true ventrolateral stripe -such as those found in Epicrionops Boulenger, 1883, Ichthyophis Fitzinger, 1826, and Rhinatrema Duméril & Bibron, 1841-but instead these Caecilia bear a series of light-colored rectangles interrupted by dark grooves, hence not touching each other. Lynch's assertion that the dermal scales of C. goweri are only found within the secondary grooves is wrong (Lynch, 2000: 327), because we have confirmed their presence in both the primary and secondary grooves (as is the case for all Colombian Caecilia with secondary grooves). Taylor (1968: 426) claimed not to have examined any Peruvian specimens of C. pachynema (Fig. 6) but still provided an illustration is of a specimen taken from "Fundo Sinchono", Loreto, Peru (Fig.  226). This specimen (USNM 119008) was later designated as the holotype of C. inca and, according to Taylor (1973), the differences in coloration, adult size, and presence of scales throughout most of the body separate it from C. pachynema. Based on their original descriptions, we find it difficult to discern these two species given that their groove counts overlap and differences in coloration can be attributed to variation. Furthermore, we have found dermal scales in other supposedly scale-less Caecilia and the average adult size can only be gauged if a series of specimens is available.

DISCUSSION
Some individuals of C. pachynema may not have secondary grooves fide Taylor (1968), a peculiarity that we corroborated during a recent visit to QCAZ, Ecuador in 2019. Variation in secondary groove number, ranging from zero to 11, could challenge the efforts to diagnose other Caecilia with overlapping counts of primary grooves, hence dentition, squamation, cephalic and terminal morphology should be examined in detail to discern other similar species. Nonetheless, C. pachynema is not the only Caecilia known for variation in the presence and number of secondary grooves, as it is also known to occur in C. abitaguae, C. guntheri, C. occidentalis, C. orientalis, and C. subdermalis (unpublished data).
Aside from the collecting efforts of Hermano Nicéforo María in Pensilvania, Caldas, in the 1940s, those of Hermano Marco Antonio Serna in the Altiplano de Medellín during the 1960s, those of Restrepo et al., (2017Restrepo et al., ( ) during 2006Restrepo et al., ( -2016, and more recently those of Dr. Mauricio Rivera-Correa in Valdivia, Antioquia, much of the montane forests of the northern Cordillera Central of Colombia (Fig. 6) have not been adequately sampled for caecilians and as a result it would seem that only seven species (C. caribea, C. guntheri, C. occidentalis, C. goweri, C. subdermalis, E. bicolor Boulenger, 1883 and M. pricei) occur near Fernández-Roldán & Lynch -A new Caecilia from Colombia the 2000 m mark. Still, we are confident that as the rate of collections increases so will the number of caecilian species in these mountains.