Tooth Formula Research Articles

Patterns of Phenetic Diversity and Taxonomy of the Ide <i>Leuciscus idus</i> (Cypriniformes, Cyprinidae) from Water Bodies of Russia and Adjacent Countries

Using the methods of population morphology, we studied the structure of phenetic diversity of the ide Leuciscus idus (L.) from the water bodies of the Russian Federation and some neighboring countries. We analysed our own collection and literature data on meristic characters of external morphology, axial skeleton, as well as the pharyngeal teeth formula. The main features contributing to population differentiation were the number of lateral line scales, total vertebrae count, caudal and pre-caudal vertebrae ratio. It was shown that the strong positive relationships of the first two features with the geographical latitude of fish habitats is associated, first of all, not with the direct influence of physical factors functionally dependent on latitude, but with particular (sub)speciation processes in river basins and dispersal of evolutionarily derived forms to the north. The results obtained are discussed in terms of evolutionary trends in the subfamily Leuciscinae and call for a taxonomic revision of the L. idus species in its current volume with elevation of the former subspecies L. idus oxianus to a species rank.

Morphology and morphometry of pharyngeal bone and teeth in cyprinid species from the Kurdistan Region, Iraq

The morphology of pharyngeal bones and teeth was determined on seven cyprinid species caught from the Greater Zab River, a tributary of Tigris River, located in the northern part of Iraq in the Kurdistan Region. Eleven morphological characters of the pharyngeal bone and teeth were identified, measured and compared from photographs of the 152 individual species collected. The relationship between pharyngeal bone total length and four-dimensional measurements of the pharyngeal bone were determined using linear regression and multivariate analysis. Results show bone characteristics of the studied species are distinctly different in terms of shape, tooth number, tooth formulae and dimensions of the pharyngeal bones. Regression analysis shows positive coefficients of TL with all parameters PL, DL, PW and DP while multivariate linear discriminate analysis shows distinct groupings of each species using non-dimensional measurements of the bone characters. The measurements gathered and application of biometric relationships to ease the identification of the cyprinid species contributes to the morphological information on cyprinid species in a data deficient region of the world. This work provides a new set of morphological characters of the pharyngeal bone and teeth of the seven cyprinid species from Northern Mesopotamia that may enable their separation from the members of their cyprinid genera.

First Scientific Record for Sivas Aquatic Systems Related to Alien Fish Species:Small-scaled Pacu; Piaractus mesopotamicus (Teleostei:Characidae)

In July 2017, three specimens of an alien fish species were caught by the amateur fishermen in Kızılırmak River at Sivas city center. One of the fish specimens was taken from the fishermen for ichthyologic examination. The morphological, metric (23 features) and meristic characters (13 features) of this specimen were determined. The alien fish is with ovoid shape and flattened laterally. Mouth is in a sub-ventral position. The tooth row is double. Teeth formula are 3,2 / 2,3 (at first row on maxil) and 2 / 2 (at second row on maxil), 3,3 / 3,4 (at first row on mandibul), 1,1 (at second row on mandibul). The number of rakers on the first gill arch is 33. The scale numbers in line lateral are 107 (on right side) and 103 (on left side). The number of branched rays of dorsal, anal, pectoral, and ventral fins are 14, 24, 14, and 7; respectively. As a result of the evaluation of morphological, metric and meristic characters, it was decided that the alien fish caught from Kızılırmak was Piaractus mesopotamicus (Holmberg, 1887) belonging to the Characidae family. This species is also called as the small-scaled pacu. P. mesopotamicus is not among to native fish fauna of Kızılırmak. It is a fish species which originated from South America and is a tropical freshwater fish. These alien fish specimens which were caught by the amateur fishermen, probably translocated from a hobbyist aquarium to this aquatic system. Both directly and indirectly, invasive fishes affect a wide range of native organisms from zooplankton to mammals across multiple levels of biological organizations ranging from the genome to the ecosystem. This study is the first scientific record for Sivas aquatic systems related to alien fish species.

3D skull modelling and description of a new baurusuchid (Crocodyliformes, Mesoeucrocodylia) from the Late Cretaceous (Bauru Basin) of Brazil.

Baurusuchidae is one of the most diverse groups of South American notosuchians, unambiguously recorded in Late Cretaceous deposits of Brazil and Argentina. The group is characterized by a reduced tooth formula, a lateromedially compressed rostrum, and a verticalized quadrate, representing one of the top predators of their faunas. Historically, skull morphology is the most employed tool to investigate the relationships of baurusuchids, as most of the species have been primarily based on cranial remains. The present study describes a new baurusuchid species from the Bauru Basin of Brazil, based on the first tridimensional digital reconstruction of individualized skull bones for Notosuchia, and discusses its phylogenetic position within the group. The new species differs from all the other known baurusuchids by a depression on the posterior portion of the nasal bearing a crest, an infraorbital crest of the jugal that extends until the anterior margin of the lacrimal, the dorsal surface of the frontal lacking a longitudinal crest or depression, and the lateral convexity of the squamosal prongs participating in the occipital wall. The new taxon is consistently positioned as sister to the remaining baurusuchines, with Aplestosuchus sordidus and Stratiotosuchus maxhechti, as successive sister-taxa to a monophyletic Baurusuchus (Ba. albertoi, Ba. Salgadoensis, and Ba. pachecoi). Our updated phylogenetic analysis helps to differentiate the two major Baurusuchidae lineages, Baurusuchinae and Pissarrachampsinae. Yet, the new species shares morphological features with both groups, suggesting the occurrence of "Zones of Variability" in the radiation of Baurusuchidae.

Jaxea kuemeli Bachmayer, 1954 (Malacostraca, Gebiidea, Laomediidae) from the Middle Miocene of Tunjice Hills (central Slovenia)

In the present paper we report on several new specimens of Jaxea kuemeli Bachmayer, 1954 from the Middle Miocene laminated sandstones from Košiše in Tunjice Hills. New and well-preserved material from shallow water environment of Laško Formation allows the re-evaluation of Jaxea cheliped morphology. The report enhances our knowledge of the variability of tooth formula in the cheliped of Jaxea kuemeli and opens questions about interspecific variations connected to temporal or ecological factors. We also discuss the environmental preferences of the species which is so far known exclusively from the Paratethys Sea.

Supernumerary teeth in the pharyngeal dentition of slow-developing zebrafish (Danio rerio , Hamilton, 1822)

Heterochrony, which is a change in the developmental rate and timing, is one of the mechanisms proposed to explain alterations in meristic characters, such as the variation in the numbers of skeletal elements between individuals within a population. To verify the possible role of heterochrony in the evolutionary transformation of the cyprinid pharyngeal tooth formula, the development of the pharyngeal dentition in zebrafish (Danio rerio) was studied under the influence of deficiency of thyroid hormones at 28°C and standard zebrafish rearing conditions. Thiourea was used to decrease the level of thyroid hormones, a treatment known to cause retardation of several developmental processes, including skeletal development and tooth formation. Retarded development resulted in a high degree of variability as well as left – right asymmetry in the dentition. Supernumerary teeth developed; these were either extending a tooth row anteriorly or were added lateral to a tooth row, or both. An addition laterally resembled the start of formation of an accessory tooth row. Compared to younger individuals, older zebrafish showed a higher number of supernumerary teeth, often associated with a broadened attachment zone on the jaws. Both anteriorly and laterally positioned supernumerary teeth were regularly displayed. These results support the hypothesis that heterochrony can affect dental characters in cyprinids, as has been suggested in the development of the skull, caudal fin and the Weberian apparatus.

The Study of Natural Saponification Processes in Preservation of Human Corpses

The natural course of evolution of the human body after death includes autolysis, putrefaction and skeletonization. Under specific environmental conditions, the body may bypass this natural path, leading to preservation, such as saponification (adipocere), lignification, mummification or refrigeration, comprising the entire body or being limited only to some parts of it. All these preservation processes have a chemical substrate, and the identification of their components may be useful in many forensic circumstances, such as clandestine activity and identification of victims in mass disasters, when pentanoic, butanoic, hexanoic acid, butanoic acid-butyl ester, hexanoic acid-ethyl ester, indole, dimethyl disulphide may be used to train human remains detection dogs. The authors present the case of a 73 years old woman who was found dead in a sewage collection basin 4 months after her disappearance in July. The autopsy revealed a mixture of cadaveric processes, some parts being disintegrated, with putrefaction and skeletonization, while other parts were preserved by saponification: areas of adipocere were found on the neck, thorax and the anterior part of the abdomen. In some instances the saponification of the corpses makes identification possible and preserves violence marks, but the combination with putrefaction burdens these goals. The identification in this case was possible using the teeth formula, keeping in mind that tooth and bones are the most resistant to putrefaction. Even though saponification makes difficult the estimation of postmortem interval, investigations of its chemical composition may be useful in this direction, as the epicoprostanol-cholesterol ratio proved to increase with the increasing of postmortem interval.

Redescription of the Tadpole ofAmeerega hahneli(Boulenger, 1884) (Anura: Dendrobatidae) with Notes on Ontogenetic Variations and Development Habitats

Ameerega hahneli is a terrestrial dendrobatid frog widely distributed in the Amazon region. The tadpole of this species was formally described based on eight specimens in the early developmental stage 25, when some of the morphological structures were still not fully developed. In this study, the tadpoles of A. hahneli are redescribed based on 78 individuals in 14 different developmental stages. Additionally, we provide data on the ontogenetic variations and development sites of tadpoles. Specimens were collected in streamside ponds and streams of non-flooded forest during the rainy season. The tadpole of A. hahneli at stage 36 is characterized by: body elongate, depressed (lateral view), and oval (dorsal view); small size (mean 23.96 mm, range 21.7-26.2 mm); oral disc anteroventral; labial tooth row formulae 1/2; marginal papillae uniseriate, triangular, and distributed only on the lower labium. Like other tadpoles of the genus, the upper jaw sheath is W-shaped with a ventral notch and the lower jaw sheath is V-shaped, the spiracle is sinistral, and the vent tube is dextral. Ontogenetic variations were observed in body size, number of marginal papillae, lateral line system and ventral coloration. Total length increased gradually from the stage 25 (14.67 mm) to stage 37 (26.70 mm), the latter being the maximum total length observed. The combination of the morphological organization of its labial tooth row formulae and the presence of triangular marginal papillae only at the posterior labium allows the A. hahneli tadpoles to be easily distinguished from all the others species of the genus Ameerega.

The southernmost range limit for the hidden angelshark Squatina occulta

Angelsharks (Genus Squatina) are distributed in the southern Southwest Atlantic Ocean between southeastern Brazil and central Patagonia. The endangered hidden angelshark Squatina occulta is reported in the literature as ranging from Espirito Santo, Brazil to Southern Uruguay. Its presence in Argentine waters has been suspected but not verified so far. This study describes and analyzes a specimen of S. occulta found in Puerto Quequen 38° 40′S - 58° 50′W, Buenos Aires Province, Argentina. An immature male of 578 mm total length and 1,450 g was collected from commercial landings of the bottom trawl fishery of Puerto Quequen. The specimen exhibited the coloration pattern, dermal denticle distribution, and tooth formula characteristic of S. occulta. Squatina guggenheim and S. argentina are already known to occur off Puerto Quequen. The present finding confirms the presence of a third species of angelshark in Argentina and constitutes the southernmost record of S. occulta.

The first articulated specimen of the Cretaceous mackerel shark Haimirichia amonensis gen. nov. (Haimirichiidae fam. nov.) reveals a novel ecomorphological adaptation within the Lamniformes (Elasmobranchii)

The first shark from the early Late Cretaceous Konservat Lagerstätte of Agoult (south-eastern Morocco) is described. The specimen consists of the anterior part of an articulated skeleton including the cephalic and branchial regions, anterior vertebrae and one pectoral fin. The well-preserved dentition of this specimen indicates that it corresponds to the fossil lamniform originally described as Odontaspis amonensis Cappetta & Case, 1975, a purported odontaspidid species of unclear affinities. The new material provides crucial anatomical data for this taxon, such as head shape, cranial structure, tooth formula, organization of the ampullary system and type of vertebra. Based on these features, this short-snouted, broad-headed shark is confirmed as a member of Lamniformes but is clearly not assignable to any of the known living and fossil genera, and is thus described as Haimirichia amonensis gen. nov. Moreover, this unique set of features, including several autapomorphies, differs sufficiently from those of odontaspidids and other lamniform families (both living and extinct) that it requires the erection of the family Haimirichiidae fam. nov. The articulated specimen of H. amonensis reveals a novel ecomorphological specialization within the Lamniformes, adding to the high disparity observed within this order. During the Cenomanian, H. amonensis was a common, widely distributed species that likely had a lifestyle similar to that of some living medium-sized coastal pelagic carcharhiniform sharks with a comparable overall morphology, such as the whitetip reef shark Triaenodon obesus.http://zoobank.org/urn:lsid:zoobank.org:pub:6B14A7F7-CBB7-4259-A339-CF2A99721FC8

한국산 전복과 6종의 치설 연구

한국산 전복과 2속 2종 및 4아종 (N. gigantea, N. madaka, N. discus discus, N. discus hannai, S. diversicolor diversicolor, S. diversicolor supertexta)을 대상으로 주사전자현미경 (SEM)을 이용하여 치설 관찰을 하였다. 그 결과 전복과 패류의 치설형은 비대칭적인 선설형 (Rhipidoglossate form)이며, 치식 (Radular formula)은 >50-5-1-5-50< 으로 중앙에 1열의 중치와 3열의 측치 그리고 50열 이상의 연치로 구성되어 있다. 이러한 치설 구조는 실험 대상종 모두 공통적인 결과로 종 또는 속 간 치설 구조의 차이는 나타나지 않았다. 그러나 각 종별 세부적인 치설 형태의 차이점은 인지되어, 이를 규명하기 위한 정밀하고 세밀한 관찰이 요구되었다. These studies were conducted to compare the radulae of six species (Nordotis madaka, N. gigantea, N. discus discus, N. discus hannai, Sulculus diversicolor diversicolor, and S. diversicolor supertexta) of the family Haliotidae in Korea using the scanning electron microscope. As a result, teeth of all species has asymmetry rhipidoglossate form and basic tooth formula of six Haliotids was >50-5-1-5-50< (one central tooth, five lateral teeth, and over the 50 marginal teeth on each side). Therefore it is difficult that all of the species can be detected sharply the difference of interspecies by comparisons of radulae.

Tribosphenic mammals from the Lower Cretaceous Cloverly Formation of Montana and Wyoming

ABSTRACTWe report a diverse assemblage of tribosphenidan mammals from several localities in the Cloverly Formation (Lower Cretaceous, Albian) of Montana and Wyoming. This unit is of historical significance for yielding well-known dinosaurs (e.g., Deinonychus antirrhopus, Tenontosaurus tilletti) and early mammals (e.g., Gobiconodon ostromi, Montanalestes keeblerorum). We provisionally identify 13 taxa (five of which are formally recognized), including Pappotherium pattersoni, a new species of the deltatheroidan Oklatheridium (O. wiblei, sp. nov.), a eutherian (Montanalestes, previously named), and two new basal tribosphenidans (Argaliatherium robustum, gen. et sp. nov., and Carinalestes murensis, gen. et sp. nov.). An unnamed taxon, represented by associated but almost edentulous dentaries, is interpreted to have had four incisors, a single-rooted canine, three premolars, and four molars, indicating that the metatherian tooth formula was established by the Albian. In addition, an indeterminate lower molar fragment preserving twinned talonid cusps and a buccal postcingulid provides the earliest evidence for Marsupialiformes. We also provide a more detailed description of the associated dentaries (holotype) of Montanalestes keeblerorum. The mammalian fauna from the Cloverly Formation shares several taxa with the roughly contemporaneous Trinity Group of Oklahoma and Texas, an observation that also applies to the dinosaur fauna, suggesting some degree of latitudinal homogeneity among described terrestrial vertebrates in this part of the North American Early Cretaceous.http://zoobank.org/urn:lsid:zoobank.org:pub:F62E498B-9E95-475B-B2E3-0CA6FC31FB2A

Radula Tooth Structure of Eight Bithyniid Snails Observed by Scanning Electron Microscopy

Eight species of the family Bithyniidae, Bithynia striatula, B. tentaculata, B. siamensis, B. leachi, B. kiusiuensis, B. misella, Bithynia sp. from Nepal, and Gabbia australis were studied for comparison of the radula structure by scanning electron microscope. Radular ribbons of B. siamensis and B. leachi had 60-70 rows, and the other species had 40-50 rows. Teeth of all species studied had symmetrical structure, i.e. a total of seven teeth (one central tooth, and one lateral and two pairs of marginal teeth on each side) in each row were observed. The basic tooth formula of eight bithyniids was 2:1:1:1:2. Numbers and shapes of cusps were slightly differ from individuals or species. The mesocone of the central tooth of B. striatula, B. tentaculata, B. siamensis and Bithynia sp. differed from those of the other species observed.

IDENTIFIKASI KARAKTERISTIK ALAT PENCERNAAN KELELAWAR PTEROPUS ALECTO DI SULAWESI BAGIAN UTARA

CHARACTERISTICS IDENTIFY OF THE DIGESTIVE ORGANS OF BAT (PTEROPUS ALECTO) IN NORTHERN SULAWESI. The study aimed to classify Pteropus alecto (Black flying foxes=paniki yaki), based on the type of feed and the digestive system. A Descriptive explorative method was used in this study. The primary data, consist of animals sample, and of laboratory identification of the shapes physical morphology and size of digestive organs. The secondary data was taken by collecting the information from bat origin region, or its habitat. The results showed, the general characteristics of bat (Pteropus alecto), both male and female were performed a hairy color black in all parts of the body (except in the wings), it has no tail, the face shape resembles a dog or fox, has sharp curved claws on thumb, also on both toes, for hanging. The body length of the observed P. alecto were ±16.4 cm (♀) and ±22.5 cm (♂), with the body weight was ± 719,87 g on male, heavier than females (± 526.5 g). The profiles gastrointestinal organs of bat, viz: the teeth, stomach, intestine, and colon. Yhe teeth formula, were I = 2/2; C = 1/1; Pm = 2/2; M = 3/4, the number of overall teeth were 34. The digestive tract organs of bat (P. alecto) were suspected bigger, longer, and heavier, than other frugivore bat types, where the length of the stomach were ± 8.45 cm (♂) and 8.04 (♀), the length of the small intestine were ± 289.3 cm (♀) and 302.42 cm (♂), and the colon were ± 24.13 cm (♀) and 27.3 cm (♂). The mostly feed types being eaten by P. alecto, namely: papaya (Carica papaya), banana (Musa paradisica), mango (Mangifera indica), soursop (Annona muricata), guava (Psidium guajava) and coconut flower (Cocos nucifera) It is oncluded, bat (Pteropus alecto) has a digestive organs system which generally similar to other monogastric animals, but it has no cecum, and no space for fermentative digestion, and where it main feed is fruits, so it can be categorized as frugivores herbivores monogastric animal (non pseudo-ruminant). Keywords: Pteropus alecto, feed type, digestive tract organs

A revision of the Rutilus complex from Mediterranean Europe with description of a new genus, Sarmarutilus, and a new species, Rutilus stoumboudae (Teleostei: Cyprinidae).

By combining morphology, ecology, biology, and biogeography with the available molecular (sequence variation of the entire mitochondrial cytochrome b gene; cyt-b) and karyology data, the taxonomy of several species of the Rutilus complex inhabiting southern Europe is revised. Rutilus stoumboudae, new species, is described from Lake Volvi, Greece. It differs from Rutilus rutilus in possessing more total GR and less branched rays in both dorsal and anal fins and in its placement in the cyt-b based phylogeny of the genus. The resurrected genus Leucos Heckel, 1843 (type species Leucos aula, Bonaparte, 1841), which according to molecular data diverged from Rutilus more than 5 million years ago, during the Messinian salinity crisis, includes five species of small size, without spinous tubercles on scales and head in reproductive males, pharyngeal teeth formula 5-5, and all show a preference for still waters. Leucos aula is the Italian species endemic in the Padany-Venetian district: L. basak is widespread in Croatia, Albania, Montenegro and former Yugoslav Republic of Macedonia (FYROM); L. albus, recently described from Lake Skadar, Montenegro, is also found in rivers Moraca and Zeta (Montenegro). L. albus differs from L. basak, its closest relative, in having more scales on the LL and less anal-fin rays; L. panosi is endemic to the western-Greece district, and L. ylikiensis is endemic to lakes Yliki and Paralimni in eastern Greece (introduced in Lake Volvi). Among the nominal species examined, Rutilus karamani, R. ohridanus, R. prespensis and R. prespensis vukovici are all junior synonyms of Leucos basak. Rutilus vegariticus is definitively regarded as junior synonym for R. rutilus. Sarmarutilus n.gen. is a monotypic genus, with Sarmarutilus rubilio as the type species. According to phylogenetic data, Sarmarutilus rubilio is basal to a cluster of species that includes Leucos basak, L. albus, L. aula, L. panosi and L. ylikiensis. Sarmarutilus possibly evolved in pre-Messinian time, in the Lago Mare, entered the Mediterranean area during the Messinian Lago Mare phase of the Mediterranean Sea and survived only in the Tuscany- Latium district. This genus differs from Leucos in having large pearl organs on the central part of head and body scales in mature males and for the habitat preference, being a riverine-adapted species. It differs from Rutilus in pharyngeal teeth formula (5-5 in Sarmarutilus and 6-5 in Rutilus), size (small in Sarmarutilus and large in Rutilus) and for the preferential habitat (riverine vs. still water). Finally, lectotypes for Leucos basak, Leucos aula, and Sarmarutilus rubilio are designated.

Reconstruction of the dentition of Propyrotherium saxeum Ameghino, 1901 (Mammalia, Pyrotheria): taxonomic and phylogenetic implications

ABSTRACT Propyrotherium saxeum is one the least known members of Pyrotheria, an enigmatic group of extinct, giant, endemic South American ‘ungulates.’ The species was originally described based upon two isolated cheek teeth and two tusk fragments. Later authors assigned additional isolated teeth to this taxon, but the position within the tooth row of all these teeth remained uncertain, preventing an accurate dental characterization and taxonomic distinction from other related species. Here we reexamine the type specimens of P. saxeum and additional materials previously reported as belonging to this species, and analyze several lots of still undescribed specimens, in order to reconstruct the cheek tooth series. Based on comparisons with better known pyrotheres, we conclude that the most probable cheek teeth formula is P2–M3/p2–m3. The cheek teeth gradually increase in size from front to back, and the upper cheek teeth have a gradual increase in loph curvature, as in Pyrotherium. All cheek teeth are bilophodont, but in premolars the anterior loph/id is transversely shorter than the posterior. All have lingual/labial cingulum/id; P3–M3 are subquadratic and three-rooted; p4–m3 are longer than wide, two-rooted, and bear a variably developed vestige of cristid obliqua. Propyrotherium is distinguishable from Griphodon and Baguatherium, but the distinction between these latter two taxa is uncertain with the current evidence. A revised cladistic analysis confirms that Propyrotherium is one of the earliest diverging pyrotheriids, but the resolution of its relationship with Griphodon and Baguatherium requires further evidence. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

A new eutriconodont mammal from the early Cretaceous Jehol Biota of Liaoning, China

A new genus and species of eutriconodont mammal, Chaoyangodens lii gen. et sp. nov., from the Dawangzhangzi bed of Yixian Formation, Lingyuan, Liaoning, is reported. The new species has a tooth formula I5-C1-P1-M3/i4-c1-p1-m4, unique among eutriconodonts in having only one premolar in lower and upper jaws, respectively, and a distinctive diastema between the canine and the premolar. Its simple incisors and reduced premolars show a mosaic combination of primitive and derived features. This new taxon adds to the diverse group of Jehol eutriconodonts. Among the known species from at least three horizons, there seems no evolutionary trend in morphology that is recognizable, except for that larger species are all from the Lujiatun bed of the Yixian Fm. A thorough and systematic analysis involving all the Jehol eutriconodonts is needed to understand their phylogenetic relationships.

A Biological Study of the Little Earth Hare, Pygeretmus pumilio (Kerr,1792), In the Golestan Province of Iran (Mammalia: Rodentia: Dipodidae)

Order Rodentia has 6 families, 32 genera and 79 species in Iran. Among them the family dipodidae are with 4 genera and 10 species. Twenty seven specimens of Little Earth Hare, Pygeretmus pumilio were caught from a sampling site at near of Voshemgir dam and around of fishery culture in the northeast of Aghghala city of Golestan province in 2001-2002. The results are as follows: head and body 72.96-94.66 (mean 85.41) mm; tail 114.20-148.80 (mean 134.33) mm; hind foot 41.62-46.74 (mean 44.38) mm; ear 18.43-24.60 (mean 21.22) mm; claw of the largest toe 1.69-2.67 (mean 2.03) mm; weight 22.54-46.60 (mean 35.05) gr. The biometery of skulls were also measured. Teeth formula is i 1/1, c 0/0, p 0/0, m 3/3. We observed 2 times birth of pups. One time (31/4/2002) four pups were born. Weight of mother was 38.75 gr. The pups are pinkish, without hairs and with closed eyes and short ears. Weight of pups were 2.22-2.37 (mean 2.29) gr. The other four pups (1/3/2002) were lighter and their weight were 1.60-1.68 (mean 1.63) gr. This species also feeds on desert plant, melon and water melon.

Morphological and taxonomic revision of species of Squatina from the Southwestern Atlantic Ocean (Chondrichthyes: Squatiniformes: Squatinidae).

The morphology and taxonomy of species of Squatina from the southwestern Atlantic Ocean are revised. Species previously considered valid, Squatina argentina (Marini, 1930), Squatina guggenheim Marini, 1936 and Squatina occulta Vooren and da Silva, 1991, are investigated and described in detail, including a morphometric and meristic study of specimens from their recorded range. The taxonomic status of the doubtful nominal species Squatina punctata Marini, 1936 was also evaluated. This species was previously considered a junior synonym of S. argentina, a junior synonym of S. guggenheim, or a senior synonym of S. occulta. Although there is much morphological similarity between Squatina species, significant differences in dermal denticle patterns, dorsal coloration, tooth formula, and size at maturity are reported, enabling the recognition of S. argentina, S. guggenheim and S. occulta as valid species, and relegating S. punctata to the synonymy of S. guggenheim. Differences in skeletal morphology between valid species are described and considered supportive of the taxonomic hypothesis, corroborating a previous study of neurocrania. Additionally, an unidentified specimen is reported, as Squatina sp., from the continental shelf of Bahia state, Brazil, recognized by having more vertebral centra and a conspicuous dermal denticle morphology on interspiracular region, features not present in other South America angelshark species. A report on the only known syntype of Squatina dumeril Le Sueur, 1818 is presented, describing features that are still preserved and designating it as lectotype. Lateral-line sensory canals, skeleton, and cranial and hypobranchial muscles for the three valid species of Squatina from the southwestern Atlantic, as well as the brain and cranial nerves of S. guggenheim, are described and illustrated.

Radular Variations in Freshwater Snails of the Family Lymnaeidae (Mollusca: Gastropoda: Basommatophora) from Northwestern Iran

The Family Lymnaeidae is comprised of large aquatic snails that are intermediate hosts of parasitic flukes. In the present study, radular morphology, teeth length, and tooth formula of field-collected lymnaeid snails including Galba truncatula (Müller, 1774), Lymnaea stagnalis (Linnaeus, 1758), Radix auricularia (Linnaeus, 1758), and Radix gedrosiana (Annandale and Prashad, 1919) were investigated. The conical and dextral freshwater snails were collected from their natural habitats in West Azerbaijan province, northwestern Iran, in fall 2010. The snails were rinsed, measured, and taxonomically identified. The radula of all specimens was extracted and stained using Mallory II. Besides the morphological variations, the mean length of radular teeth significantly increased with the body size of the examined lymnaeid snails. Morphometric investigation indicated that the mean length of lateral (L) (427.86 ± 6.9 µm) and marginal (M) (427.82 ± 6.86 µm) radular teeth of Lymnaea stagnalis differed significantly from those of other examined lymnaeid snails. The average number of radular M teeth and L teeth were the highest in R. auricularia and L. stagnalis, respectively. The specimens with smaller body size had the most transverse teeth rows (G. truncatula, 115.6 ± 3.7 µm). It was concluded that radular teeth morphology and morphometry within lymnaeid species could be one of the character sets for classification of lymnaeid snails.