LEIUPERIDAE, Bonaparte, 1850

Candioti, M. Florencia Vera, 2007, Anatomy of anuran tadpoles from lentic water bodies: systematic relevance and correlation with feeding habits, Zootaxa 1600, pp. 1-175 : 96-101

LEIUPERIDAE

Physalaemus santafecinus . Perotti and Céspedez (1999) described the oral apparatus and buccopharyngeal cavity of this species.

Chondrocranium and hyobranchial skeleton (N = 5, stages 32 and 33. Fig. 54). The chondrocranium of these larvae represents 50% of the body length. The maximum width is at the plane of the posterior part of the subocular bar. The suprarostral cartilage has a single, V-shaped corpus, which is dorsally fused to the alae. These are well-defined, ventrally rounded, and bear well-developed dorsalis anterior and posterior processes. The trabecular horns correspond approximately to 25% of the total length of the chondrocranium and diverge from the ethmoid plate. They are narrow and uniformly wide. The cranial floor is completely cartilaginous, with thin cartilage in the central area. The carotid foramen is visible, whereas the craniopalatine is not identifiable because of the light chondrification of the intertrabecular plate. In the posterior margin of the cranial floor, the notochordal canal extends 21% of the chondrocranium length. The orbital cartilages and the taeniae tecti marginales are not developed in the stages analyzed. The otic capsules are ovoid, occupy nearly 26% of the chondrocranium total length, and bear a small anterolateral process. The tectum synoticum is not developed. The palatoquadrate has a short and wide articular process, a tall, thin and triangular muscular process, and a smooth subocular bar, slightly wider caudally. In some specimens there is a small non-chondrified portion in the posterior part of the bar. The palatoquadrate attaches to the braincase via three points: the quadratocranial commissure, with a long quadratoethmoid process, the quadratoorbital commissure, and the ascending process, attached to the floor of the cranial cavity. In the lower jaw, Meckel’s cartilages are Lshaped, with three processes: dorsomedial, ventromedial, and retroarticular. The infrarostral cartilages are short, rectangular and independent. In the hyobranchial skeleton, the ceratohyals are long and have a tall, triangular anterior process, a thin, pointed, medially directed anterolateral process, an acute lateral process, and a wide, tall posterior process; the articular condyle is a quadrangular, robust protuberance visible on the dorsal surface. The ceratohyals are joined medially by the pars reuniens. The basihyal is absent and the basibranchial is short and bears a small urobranchial process (24% of the basibranchial length). The hypobranchial plates are flat and subquadrangular, and they articulate medially leaving an ovoid posterior gap. The ceratobranchials are long, thin, and have numerous lateral projections. They are distally joined by terminal commissures. Four cartilaginous spicules arise dorsally from each ceratobranchial, the fourth one being reduced.

Musculature (N = 5, stages 32 and 33. Table 16 and Fig. 55). Thirty-three muscles appear in this species.

Oral apparatus and buccopharyngeal cavity (N = 2, stages 32 and 33. Figs. 56 and 57). The oral disc width represents 22% of the body length, and gape width reaches 19% of the body length. The lateral margins have deep indentations in the commissural region. The papillar margin is simple and interrupts in a wide dorsal gap that occupies nearly the entire upper lip. Papillae are conical with smooth, rounded tips. The rostrodonts are well-developed and keratinized, thick, and finely serrated. The serrations of the suprarostral are slightly shorter than those of the infrarostral. The keratodonts are arranged in four rows, two upper (anterior) and two lower (posterior), resulting in a LTRF 2(2)/2(1). The first three rows have approximately the same length, whereas P2 is slightly shorter. The keratodonts are long, with three distinctive regions, sheath, body and head. The head is slightly convex, oblong and with 4–6 cusps. In the buccal roof, the prenarial arena shows a bilobate ridge and groups of pustules. The choanae are large, elongate and obliquely oriented at an angle of about 28º from the transversal line. The anterior margin has small prenarial papillae, and the narial valve is thick and well-developed. The postnarial arena shows two pairs of flat, tall papillae, the medial pair larger that one lateral one. The lateral ridge papillae are tall, wide, flat and trifurcate. The median ridge is trapezoid, with a pustulate free margin and small pustules on its ventral surface. The buccal roof arena is delimited on both sides by 5–6 tall, conical marginal papillae. Numerous pustules scatter among the papillae. Large secretory pits appear in a V-shaped array, on the posterior region of the buccal roof. The dorsal velum is short, smooth, and medially interrupted. In the buccal floor, posterior to the infrarostrodonts, there are 6–8 pustules transversely aligned. Posteriorly, two pairs of infralabial papillae appear: the anterior pair, on the Meckel’s cartilage, is hand-like and large, and the medial pair includes smaller, trifurcate papillae. On the tongue anlage, there is a single conical lingual papilla. The buccal floor arena is delimited by 15 papillae, four paired and seven odd; two pairs are bifid and the remaining, conical, with different heights. Numerous pustules are scattered among the papillae. The buccal pockets are deep and transversally disposed. The ventral velum is long and supported by spicules; it has three pronounced marginal projections on the filer plates, and it lacks a median notch. Secretory pits appear on the posterior ventral surface of the velum.

Gut content (N = 10, stages 32–35. Tables 21 and 22). The gut content was mainly composed of insects remnants and desmids, and the more frequent prey sizes were those between <1–9% of the tadpole body size.