Liophis Miliaris Research Articles

Daily Activity of Neotropical Dipsadid Snakes

Abstract. The daily activity of nine dipsadid snakes from southeastern Brazil was characterized using captive specimens monitored by a digital video system. Six species (Apostolepis assimilis, Erythrolamprus aesculapii, Liophis miliaris, Philodryas patagoniensis, Thamnodynastes strigatus, and Tomodon dorsatus) were diurnal and three species (Atractus pantostictus, Oxyrhopus guibei and Sibynomorphus mikanii) were nocturnal. The daily activity pattern was highly variable among species. However, intra-specific variation in both period and activity pattern was observed in some of the studied species. Although activity period is usually conservative within lineages, our results indicate that activity pattern might be strongly influenced by biotic or abiotic factors.

Helminths of Liophis miliaris (Squamata, Dipsadidae): a list of species and new records

Summary In order to have better knowledge of the parasites of the common water snake Liophis miliaris (Linnaeus, 1758), a checklist of its helminths was produced based on a review of the literature and new records of worms identified during the course of a parasitological survey combining data from stool analysis (n = 22) and necropsies (n = 8) of specimens of this snake from Muriaé, state of Minas Gerais, Brazil. Thirty-one helminth species (two acanthocephalans, one cestode, 11 nematodes and 17 trematodes) were so far reported in L. miliaris in the Neotropical region, already including the records in the present study of Acanthorhabdias acanthorhabdias Pereira, 1927, Paracapillaria (Ophidiocapillaria) cesarpintoi (Freitas & Lent, 1934) and Strongyloides ophidiae Pereira, 1929. Taxonomic comments on these nematode species are given, and areas of occurrence of A. acanthorhabdias and P. cesarpintoi are expanded in southeastern Brazil. In addition, factors related to parasite richness of L. miliaris, which is likely related to its aquatic habits, are discussed.

New Hosts and Localities for Trematodes of Snakes (Reptilia: Squamata) from Minas Gerais State, Southeastern Brazil

Six species of trematodes were recovered from 5 species of snakes from the state of Minas Gerais, southeastern Brazil. Renifer heterocoelium was found in Wagler's snake, Xenodon merremii, and the cat-eyed night snake, Leptodeira annulata. Opisthogonimus fonsecai, and Opisthogonimus fariai were obtained, respectively, from X. merremii and the common water snake, Liophis miliaris. Ophiodiplostomum spectabile was also found in Li. miliaris. Styphlodora gili was found in the two-headed sipo, Chironius bicarinatus and Travtrema stenocotyle was found in the Brazilian lancehead, Bothrops moojeni. New localities are reported and Le. annulata and C. bicarinatus are, respectively, new hosts for R. heterocoelium and S. gili.

Serpentes encontradas mortas em rodovias do estado de Santa Catarina, Brasil

Estradas causam diversos impactos aos ecossistemas, incluindo perda e fragmentação de hábitat, alteração da paisagem natural e morte de animais, sendo que pouco se sabe sobre o impacto destas mortes sobre as populações. A fauna de serpentes do Estado de Santa Catarina é a menos estudada do Sul do Brasil, não havendo estudos abordando serpentes atropeladas. Neste trabalho apresentamos dados sobre serpentes encontradas mortas em diversas estradas do Estado entre os anos de 2003 e 2008. Foram registrados 165 exemplares pertencentes a 38 espécies que correspondem a 50% das serpentes com ocorrência esperada para o Estado de Santa Catarina. As quatro espécies mais freqüentes foram Philodryas patagoniensis (N= 22; 13,33%), Liophis miliaris (n = 21; 12,72%), P. aestiva (n = 13; 7,87%) e Bothrops jararaca (n = 12; 7,27%), que somadas representam cerca de 41% das serpentes encontradas mortas. Amplia-se ao sul a distribuição de Imantodes cenchoa em cerca de 60km.

The snake community of Serra do Mendanha, in Rio de Janeiro State, southeastern Brazil: composition, abundance, richness and diversity in areas with different conservation degrees

We studied and compared parameters of the snake community of the Serra do Mendanha, Rio de Janeiro State, southeastern Brazil (22 degrees 48'-22 degrees 51' S and 43 degrees 31'-43 degrees 28' W), such as: abundance distribution, richness, species diversity and biomass, between forested areas, areas under regeneration and agriculture areas (banana plantations); to obtain information about the natural history and facilitate the development of future research. For capturing the snakes we used: pitfall traps, drift-fences and visual search (diurnal and nocturnal) along four transects for each habitat. The captured snakes were measured with a tape and caliper, weighed with dynamometers and sexed with the use of a catheter. The animals marked (with ventral scales cut) were released for posterior recapture. One individual per species was fixed and deposited at the Museu Nacional, Rio de Janeiro. We undertook an effort of 840 man/hour, and captured a total of 207 snakes belonging to 25 species (Colubridae 80.2%, Elapidae 12.6%, Viperidae 6.3% and Boidae 0.9%). The most abundant were: Liophis miliaris (n = 33), Micrurus corallinus and Chironius fuscus (both with n = 26); the least abundant: Elapomorphus quinquelineatus, Siphlophis compressus and Tropidodryas serra (all with n = 1). The species that contributed the greatest biomass were Spilotes pullatus (7,925 g), Chironius laevicollis (4,694 g), Liophis miliaris (3,675 g) and Pseustes sulphureus (3,050 g); those that contributed the lowest biomass were: Siphlophis compressus, Tropidodryas serra (both with 4 g) and Elapomorphus quinquelineatus (3 g). We found significant differences between the sampled habitats at the Serra do Mendanha (undisturbed forest, secondary forest and banana plantations). The results showed that a great reduction in the abundance, richness, diversity and biomass of the snakes occurs when the native forest is replaced by banana plantations.

Overview of Reproductive Strategies in Xenodontini (Serpentes: Colubridae: Xenodontinae) with New Data for Xenodon Neuwiedii and Waglerophis Merremii

Reproductive patterns are highly variable among Neotropical colubrids. Snakes of the Tribe Xenodontini are widely distributed in South America and show continuous reproductive cycles in many areas. We report interspecific and intraspecific variation in reproductive traits among these snakes and also show that seasonal cycles occur mainly in cooler areas. Clutch size relative to body size is similar among species, but Erythrolamprus spp. seem to lay fewer eggs than other species, and Waglerophis merremii from southeastern and southern Brazil lay more eggs than other species. Newborn Erythrolamprus are larger than all other Xenodontini, which may be related to ophiophagy. As in many other snakes, adult females are larger than males, but both sexes attain maturity with a proportionally similar body size. The sexual size dimorphism index is generally lower in smaller bodied species, and combat may be absent in the tribe. Male reproductive cycles are less well studied but seem to be more conservative, being continuous in all species studied (W. merremii, Xenodon neuwiedii, and Liophis miliaris). Phylogeny has an important role in reproductive patterns but climate and life-history traits can also influence tropical and subptropical species.

Snakes from coastal islands of State of São Paulo, Southeastern Brazil

There are relatively few studies on snake fauna from coastal islands of the State of São Paulo (SSP), Southeastern Brazil and the number of species housed in Brazilian institutional zoological collections is relatively limited. In Brazil, for the first time, a snake inventory for eighteen islands of coastal SSP is presented. Here we record data from sampling on eleven islands as well information on vouchered species in the main herpetological collections. Thirty-six species from four families: one Boidae, thirty Colubridae, one Elapidae and four Viperidae from eighteen islands are listed as well as the thirteen new island records for snakes. Relative abundance categories were used for species rarity: common, infrequent and rare; 44.4% of the snakes with voucher specimens were considered rare. The most common species in twelve of the eighteen islands was Micrurus corallinus; in eleven of the eighteen islands were Bothrops jararaca and Liophis miliaris; in ten of the eighteen islands were B. jararacussu and Chironius bicarinatus. The most common snake species on coastal islands were Micrurus corallinus which was found in twelve of the eighteen islands, followed by Bothrops jararaca and Liophis miliaris found on eleven of the eighteen islands and B. jararacussu and Chironius bicarinatus which were found in ten of the eighteen islands studied. There are seven new records of snake species for Cardoso Island (25° 05’ S and 047° 59’ W): C. bicarinatus, C. multiventris, Dipsas petersi, Echinanthera bilineata, E. cephalostriata, Helicops carinicaudus and Xenodon neuwiedii; three new records for Comprida Island (24° 54’ S and 47° 48’ W): B. jararacussu, C. bicarinatus and H. carinicaudus; one for Anchieta Island (23° 32’ S and 045° 03’ W): Spilotes pullatus; one for Couves Island (23° 25’ S and 44° 52’ W): L. miliaris; one for Porcos Island (23° 23’ S and 44° 54’ W), B. jararaca. The endemic species B. alcatraz from Alcatrazes Island and B. insularis from Queimada Grande Island are considered endangered species by IUCN. Snake fauna on Monte de Trigo Island are extinct. The fragility of insular snake fauna needs more attention for environmental conservation, since 52.0% of snake species preys on amphibians, highlighting the importance of forest conservation.

Interpopulational variation in sexual dimorphism, reproductive output, and parasitism of Liophis miliaris (Colubridae) in the Atlantic forest of Brazil

AbstractSexual maturity, sexual dimorphism, reproductive output, and parasitism of the colubrid snake Liophis miliaris were compared among populations inhabiting four regions of Brazil: (1) northern coastal Atlantic forest, (2) southern coastal Atlantic forest, (3) northern inland Atlantic forest (4) southern inland Atlantic forest. Females delayed maturity and attained larger body sizes than males in all regions. Males and females from northern Atlantic forest were smaller and attained maturity with a smaller body size than males of other regions. The sexual size dimorphism index ranged from 0.19 to 0.23 and was lowest in the northern Atlantic forest. There was no sexual dimorphism in head length in any of the populations studied. Clutch size was similar in all populations and increased with maternal body size. The reproductive frequency was lower in the northern coastal Atlantic forest and in contrast to the other regions, tended to increase with female body size. The nematoda Ophidiascaris sp. and cystacanths of Oligacanthorynchus spira (Acanthocephala) occurred equally in both sexes. Fewer snakes from the northern coastal Atlantic forest were infested by parasites compared to the other regions and parasitism apparently did not influence reproduction.

Liophis miliaris intermedius (Henle and Ehrl, 1991) Is Actually Liophis reginae (Serpentes: Colubridae)

A recently described taxon of the snake genus Liophis (Liophis miliaris intermedius Henle and Ehrl 1991), is actually Liophis reginae.

Seasonal activity of snakes in the Atlantic forest in southeastern Brazil

AbstractSeasonal abundance of some snake species from the Atlantic forest in southeastern Brazil was inferred from collection data gathered throughout twelve years at the Instituto Butantan in São Paulo, Brazil. The number of collected individuals of Chironius spp., Liophis miliaris, Spilotes pullatus, Tropidodryas spp., Micrurus corallinus, and Bothrops jararaca was significantly higher during the rainy season, whereas the number of Sibynomorphus neuwiedi was higher during the dry season. Erythrolamprus aesculapii, Xenodon neuwiedii, Tomodon dorsatus and Bothrops jararacussu did not show significant differences in the number of individuals collected at each of these seasons. Seasonality in captures may result from seasonal activity patterns. Food availability, tolerance to climatic conditions, reproductive cycle, and phylogenetic constraints are considered the main factors responsible for the observed patterns. A multivariate approach is recommended for analysis of annual activity.

The amino acid sequences of two alpha chains of hemoglobins from Komodo dragon Varanus komodoensis and phylogenetic relationships of amniotes.

To elucidate phylogenetic relationships among amniotes and the evolution of alpha globins, hemoglobins were analyzed from the Komodo dragon (Komodo monitor lizard) Varanus komodoensis, the world's largest extant lizard, inhabiting Komodo Islands, Indonesia. Four unique globin chains (alpha A, alpha D, beta B, and beta C) were isolated in an equal molar ratio by high performance liquid chromatography from the hemolysate. The amino acid sequences of two alpha chains were determined. The alpha D chain has a glutamine at E7 as does an alpha chain of a snake, Liophis miliaris, but the alpha A chain has a histidine at E7 like the majority of hemoglobins. Phylogenetic analyses of 19 globins including two alpha chains of Komodo dragon and ones from representative amniotes showed the following results: (1) The a chains of squamates (snakes and lizards), which have a glutamine at E7, are clustered with the embryonic alpha globin family, which typically includes the alpha D chain from birds; (2) birds form a sister group with other reptiles but not with mammals; (3) the genes for embryonic and adult types of alpha globins were possibly produced by duplication of the ancestral alpha gene before ancestral amniotes diverged, indicating that each of the present amniotes might carry descendants of the two types of alpha globin genes; (4) squamates first split off from the ancestor of other reptiles and birds.

Primary structure of hemoglobin from cobra Naja naja naja.

Cobra snake Naja naja naja hemoglobin shows four bands on Triton electrophoresis. We present the primary structure of one alpha and one beta chain. The separation of polypeptide chains was achieved by ion exchange chromatography on carboxymethyl cellulose column. The amino acid sequence was established by automatic Edman degradation of the native chains and tryptic and hydrolytic peptides in a gas-phase sequencer. The structural data are compared with those of human and other reptile hemoglobins and reveal not only large variations from human but within reptiles. The amino acid exchanges involve several subunit contacts and heme binding sites. This is the first study on the hemoglobin of a land snake. There are only two amino acid sequences of sea snake hemoglobin (Microcephalophis gracilis gracilis and Liophis miliaris) reported in the literature.

Dimer-tetramer transition in hemoglobins from Liophis miliaris—II. Evidence with the stripped proteins

1. 1. Whole Liophis miliaris hemolysate stored under refrigeration at pH 7 becomes progressively deoxygenated and presents two hemoglobin forms of mol. wts 32,500 and 64,000, consistent with oxydimers and deoxytetramers respectively. 2. 2. The Hill plot determined at pH 6.5 considering oxygen pressure capable to saturate up to 50% of the hemoglobin shows a coefficient value of n H = 2.06, whereas that found at higher oxygen pressure was n H = 0.85. 3. 3. The apparent Bohr effect of about ΔH + = −0.4 in the stripped hemoglobin was explained by the increase of co-operative deoxytetramer T-state/non-co-operative ratio as a function of proton concentration.

The Amino Acid Sequences of the α and β Chains of Hemoglobin from the Snake, Liophis Miliaris

The hemoglobin of Liophis miliaris has unusual properties. The hemoglobin is dimeric in the oxy form, and the cooperativity of O2 binding is very low, but both the Bohr effect and cooperativity are greatly enhanced in the presence of ATP (Matsuura, M. S. A., Ogo, S. H., and Focesi, A., Jr. (1987) Comp. Biochem. Physiol. 86A, 683-687). Four unique chains (2 alpha, 2 beta) can be isolated from the hemolysate. The amino acid sequences of one alpha and one beta chain have been determined in an effort to understand the functional properties. Comparison of the sequences with those of the alpha and beta chains of human Hb shows the following. (i) All 7 of the residues in the beta chain normally conserved in globins are identical to those of the human chain: Gly(B6), Phe(CD1), His(E7), Leu(F4), His(F8), Lys(H10), and Tyr(HC2), except that the distal His(E7) has been replaced by Gln in the alpha chain. (ii) All heme contact residues in the beta chain are identical with those in the human chain, but two differences are present in the alpha chain: the distal His(E7) is replaced by Gln and Met(B13) by Leu. (iii) All residues that form the binding site for organic phosphates are identical to those in human Hb. (iv) The major residues that contribute to the normal Bohr effect in human Hb, Asp-beta 94, His-beta 146, and Val-alpha 1 are conserved. (v) All beta chain residues at the alpha 1 beta 2 interface are identical with those in the human chain except two: Glu(G3)----Val and Glu(CD2)----Thr; these differences in charged residues may explain the dissociation to dimers. (vi) The 23 residues of the alpha chain in the alpha 1 beta 2 contact region are identical with those of the human chain except three: Phe(B14)----Leu, Thr(C3)----Gln and Pro(CD2)----Ser. (vii) A total of 17 differences occur at the alpha 1 beta 1 interface, 11 in the alpha chain and 6 in the beta chain.

Dimer-tetramer transition in hemoglobins from Liophis miliaris—I. Effect of organic polyphosphates

1. 1. Hemoglobin from the water-snake Liophis miliaris in the stripped form presents high oxygen affinity of about P 50 = 1 mmHg and Hill coefficient of about 1.0 at pH from 6.8 to 8.5. 2. 2. In the presence of ATP such values become P 50 = 20 mmHg and n H about 2.0, respectively, at low pH from 6.5 to 7.5. 3. 3. When the pH increases an abrupt decrease of both P 50 and n H values occurs falling close to those found for the stripped hemoglobin. 4. 4. Gel-filtration in Sephadex G-100 equilibrated with 0.05 M Tris-HCl buffer containing 1 mM EDTA of the stripped hemoglobin show the presence of only one component of mol. wt of about 32,500 dt similar to the dimer of human hemoglobin A. 5. 5. The deoxy form of the dimer previously treated with ATP and placed on Sephadex column in the same condition but containing 1 mM IHP emerges as tetramer with mol. wt similar to that found for human hemoglobin, i.e. of about 65,000 dt. 6. 6. Results of the multiplicity of the snake hemoglobin, as well as the large alkaline Bohr effect in the presence of ATP previously reported, seems to be inconsistent due to the dimer-tetramer transition that occurs when ATP is bound to the stripped hemoglobin. 7. 7. A molecular mechanism involving the dimer-tetramer transition is proposed to described the oxygen transport in these animals.

Content of organic polyphosphates and their allosteric effects on haemoglobins from the water-snakes Helicops modestus and Liophis miliaris

1. 1. The ion-exchange Chromatographie analysis of the red cell nucleotides of two water-snakes with different degrees of adaptation to water showed a ratio ATP/GTP of about 2.3 in the more aquatic species Helicops modestus and of about 0.7 in Liophis miliaris. 2. 2. The haemoglobin oxygen affinity assayed in the presence of ATP, GTP, DPG and IHP in haemolysate from both snakes were determined as a function of pH. The Bohr effect values were always found to be increased in comparison with the stripped haemolysate, becoming about 1.5 times higher in L. miliaris compared with H. modestus by the nucleotide treatment. 3. 3. The Hill coefficient calculated from the slope of the haemoglobin binding curves was consistent with an increase in the protein cooperativity in the presence of the nucleotides assayed. The very low n H values of about 1.2 in absence of the effectors became close to 2.0 in their presence. 4. 4. The data of nucleotide Chromatographie analysis were compared to those found in fishes with bimodal respiration.

Taxonomic Status of the South American Snakes Liophis miliaris, L. amazonicus, L. chrysostomus, L. mossoroensis and L. purpurans (Colubridae: Serpentes)

Liophis miliaris is shown to be one of several widely distributed species of Liophis in South America; it is extremely abundant in eastern Brazil. Liophis miliaris was originally described by Linnaeus in 1758, and 16 later named taxa are shown to be conspecific with it, including the currently recognized species L. amazonicus, L. chrysostomus, L. mossoroensis and L. purpurans. All populations were analyzed statistically and the pertinent data for scale features are presented. Gans' (1964) work on L. miliaris from the southern part of its range was well done and some of his data is summarized herein. Gans' restriction of the type locality of L. miliaris to Santos, Brazil, is rejected, and the true type locality is suggested to be in the coastal savannah of the Guiana Shield. The latter determination is based upon the historical evidence surrounding the early collections of King Adolf and King Fredrik. The taxonomic realignments are in accordance with the physiographic, edaphic and/or climatic factors that appear to govern the geographic variation expressed by L. miliaris.

Effect of body size and temperature on oxygen uptake in the water snakes Helicops modestus and Liophis miliaris (colubridae)

1. 1. Oxygen uptake during rest was measured in the water snakes Helicops modestus and Liophis miliaris and related to body size and temperatures between 10–35°C at 5°C intervals. 2. 2. The relationships between oxygen uptake and body size at 25°C is expressed by the relation v ̇ o 2 = 0.411 BW 0.560 for H. modestus and V ̇ o 2 = 0.339 BW 0.647 f 3. 3. The significantly higher b value ( v ̇ o 2 = aBW b ) for L. miliaris may be related to the size attained by the fully grown specimens as well as to the larger lung surface area. 4. 4. There was no significant difference between slopes of males and females despite sexual dimorphism in size in both species. 5. 5. When the exponent b was estimated at various temperatures and compared with the value at 25°C the differences were not significant for any of the species. 6. 6. H. modestus and L. miliaris showed a metabolic plateau between 25 and 30°C, and within this temperature range there were significant differences in the b values between species.

The effect of inspired oxygen tension on oxygen uptake and tolerance to anoxia in the water snakes Helicops modestus and Liophis miliaris (Colubridae)

1. 1. The effect of oxygen tension, p o 2, on oxygen uptake and tolerance to anoxia have been studied by exposure in nitrogen atmosphere and diving in the water snakes Helicops modestus and Liophis miliaris, at 25°C. 2. 2. The critical P o 2, was the same (70mmHg O 2) for both species, but below that tension H. modestus showed a higher degree of dependence on P o 2. 3. 3. Anoxia tolerance time was longer (14 min for H. modestus and 4 min for L. miliaris) during forced dive than during exposure to a 100% nitrogen atmosphere. No difference was found in pre- and post-forced dive oxygen uptake values in both species. 4. 4. The maximum duration of a voluntary dive was shorter than the mean tolerance time to forced dives in L. miliaris. but longer in H. modestus. 5. 5. H. modestus, the more aquatic species, is significantly more tolerant of complete anoxia (100% N 2 exposure) and submersion.

Kinetics of oxygen and carbon monoxide binding to the hemoglobins of the water snakes Liophis miliaris and Helicops modestus

1. 1. Liophis miliaris and Helicops modestus are water snakes having different respiratory adaptiations to their specific habitats. L. miliaris is more active and spends more time on land than H. modestus . Knowledge of the equilibrium and kinetics of ligand binding to their hemoglobins leads to better understanding of molecular aspects of this adaptation. 2. 2. Both snakes contain several hemoglobin types in their blood. Studies on the kinetics of oxygen dissociation and carbon monoxide combination with these hemoglobins were performed by stopped-flow and flash-photolysis experiments at various pH values, both in the presence and absence of adenosine triphosphate. 3. 3. The oxygen dissociation kinetics of L. miliaris hemoglobins show a strong pH dependence and cooperative interactions between chains are indicated by autocatalytic time-courses at pH 7.0. In contrast, H. moledstus hemoglobins show nearly pH independent rate constants for oxygen dissociation and cooperative interactions between chains were not apparent. The hemoglobins of H. modestus show increased pH dependence in the presence of adenosine triphosphate. 4. 4. The carbon monoxide combination kinetics differ for the hemoglobins of L. miliaris and H. modestus in general agreement with the differences found in the kinetics and equilibria of oxygen binding. Both the kinetic and steady-state difference between these hemoglobins may be advantageous in light of the behavioral differences of these two water snakes.