Tadpole Description of Leptobrachella petrops (Rowley, Dau, Hoang, Le, Cutajar et Nguyen, 2017) (Anura: Megophryidae), an Endemic Species of Vietnam

Leptobrachella petrops (Rowley, Dau, Hoang, Le, Cutajar et Nguyen, 2017) was recently described from northern Vietnam. The tadpoles of this endemic species were collected for the first time from its type locality in Cham Chu Nature Reserve, Tuyen Quang Province. Taxonomic identification was based on a fragment of 16S rRNA gene of the newly collected tadpole and sequences of the type series obtained from GenBank. Morphological characters of the tadpoles (Gosner stages 25, 28, 35, 36, 43, 44, and 45) are as follows: Size medium, body elliptical, elongated, eyes are dorsolateral, narial apertures with characteristic gently rounded rims, slightly lifted above body surface, breathing hole on the left, vent tube dextral, separated from body and attached to lower fin, tail length exceeding two times body length, both upper and lower tail fins reach maximum height in posterior third, tip of tail pointed; dorsal surface olive-brown with distinct whitish-golden specklings, the tail has large black spots, ventral surface opaque-white, internal gills distinctly reddish. LTRF: 4(2 – 4)/3(1 – 2). In addition, we compare the tadpoles of Leptobrachella petrops with those of other species in the genus Leptobrachella.

Anesthetic management of a patient with severe aortic regurgitation undergoing reoperation for ascending aorta false aneurysm using hypothermia: prevention of ventricular fibrillation by nifekalant

Background To prevent cardiac collapse and to protect cerebral function, hypothermic cardiopulmonary bypass is established before resternotomy. However, ventricular fibrillation under hypothermia facilitates left ventricular distension, which causes irreversible myocardial damage when the patient has aortic regurgitation. We report a case of successful management in preventing ventricular fibrillation under hypothermia by using nifekalant. Case presentation A 56-year-old male, who had been performed a David operation, was scheduled for a Bentall operation for a pseudo aortic aneurysm with severe aortic regurgitation. After inducing anesthesia, we administered intravenous nifekalant and a vent tube was inserted into the left ventricle under one-lung ventilation. Extracorporeal circulation was established and resternotomy started after cooling to 27 °C. Although severe bradycardia and QT prolongation were observed, ventricular fibrillation did not occur until aortic cross-clamping. Conclusion Combining maintaining cerebral perfusion and avoiding left ventricle distension during hypothermia was successfully managed with nifekalant in our redo cardiac patient with aortic regurgitation.

Metabolic differences between symbiont subpopulations in the deep-sea tubeworm Riftia pachyptila

The hydrothermal vent tube worm Riftia pachyptila lives in intimate symbiosis with intracellular sulfur-oxidizing gammaproteobacteria. Although the symbiont population consists of a single 16S rRNA phylotype, bacteria in the same host animal exhibit a remarkable degree of metabolic diversity: They simultaneously utilize two carbon fixation pathways and various energy sources and electron acceptors. Whether these multiple metabolic routes are employed in the same symbiont cells, or rather in distinct symbiont subpopulations, was unclear. As Riftia symbionts vary considerably in cell size and shape, we enriched individual symbiont cell sizes by density gradient centrifugation in order to test whether symbiont cells of different sizes show different metabolic profiles. Metaproteomic analysis and statistical evaluation using clustering and random forests, supported by microscopy and flow cytometry, strongly suggest that Riftia symbiont cells of different sizes represent metabolically dissimilar stages of a physiological differentiation process: Small symbionts actively divide and may establish cellular symbiont-host interaction, as indicated by highest abundance of the cell division key protein FtsZ and highly abundant chaperones and porins in this initial phase. Large symbionts, on the other hand, apparently do not divide, but still replicate DNA, leading to DNA endoreduplication. Highest abundance of enzymes for CO2 fixation, carbon storage and biosynthesis in large symbionts indicates that in this late differentiation stage the symbiont’s metabolism is efficiently geared towards the production of organic material. We propose that this division of labor between smaller and larger symbionts benefits the productivity of the symbiosis as a whole.

Tadpole morphology of the white-eyed toad Leptobrachium leucops Stuart, Rowley, Tran, Le & Hoang 2011 (Anura: Megophryidae) in Bidoup – Nui Ba National Park, Lam Dong province

We describe the tadpole morphology of the white-eyed megophryd, Leptobrachium leucops Stuart, Rowley, Tran, Le & Hoang 2011 based on specimens originating from Bidoup – Nui Ba National Park, Lam Dong Province, Vietnam. The description is based on larva in developmental stages 25 - 41, which were bred at the University of Science, Vietnam National University-Ho Chi Minh City. Tadpoles of Leptobrachium leucops live in slow-flowing water - benthic with the body color from brown-black to black. Body oval shape in lateral view, dorsolaterally positioned eyes. Spiracle sinistral and leftlateral positioned. Vent tube medially located at body end, ventrally positioned. Oral disk ventrally positioned and bordered by a papillae row, in general, the keratodont row formulae of the is 1(5+5)/(4+4)1. Body length and oral disk width increase during developmental stages while tooth density decreases gradually and disappeare at the stage of 41.

A simplified table for staging embryos of the pipid frog Pipa arrabali

ABSTRACT Pipa is a Neotropical genus of frogs that dwell in freshwater environments. It includes four species that lack free-swimming larvae (P. aspera, P. arrabali, P. pipa, and P. snethlageae) and three with tadpoles (P. carvalhoi, P. myersi, and P. parva). Developmental tables such as the one proposed by Nieuwkoop and Faber might be useful for Pipa species with tadpoles. However, for the other Pipa species, to determine stages by this table or by any of the tables already prepared for frogs without tadpoles (e.g., Crinia nimbus, Eleutherodactylus coqui, and Oreobates barituensis) is impossible. By using embryonic, juvenile, and subadult specimens, we generated a staging table for P. arrabali, from the moment limb buds were first observed until birth, based on diagnostic features such as snout-vent length; growth, morphology, and reabsorption of the external tail; growth and differentiation of fore and hind limbs; development of intestine and vent tube; position of the angle of the mouth relative to nostrils and eyes; and color of preserved individuals. Based on these observations, we discuss some noteworthy traits (e.g., posture of hands and feet). We also compare the pattern of development of P. arrabali with that of other anuran species (with and without tadpoles).