Two new species of Camallanus (Nematoda: Camallanidae) from freshwater turtles in Queensland, Australia.

We describe 2 new species of Camallanus (Nematoda: Camallanidae) from freshwater turtles collected in Queensland, Australia: Camallanus nithoggi n. sp. from Elseya latisternum (Gray) and Camallanus waelhreow n. sp. from Emydura krefftii (Gray), Emydura macquarrii (Gray), and Em. macquarrii dharra Cann. The only Camallanus sp. previously reported from turtles is C. chelonius Baker, 1983 (all other species in the family have been transferred to Serpinema). The 2 new species described here differ from C. chelonius in the number of male preanal papillae (7 vs. 6 in C. chelonius), the number of male postanal papillae (5 vs. 4 in C. chelonius), and the number of buccal capsule ridges. Additionally, we removed the tissues overlying the buccal capsule and used scanning electron micrographs (SEM) to show that the peribuccal shields extend laterally from the buccal capsule, the basal ring is separated from the buccal capsule by a narrow isthmus, and there is a buttress along the lateral margin of the buccal capsule that has not previously been observed in species of Camallanus

On the constraints violation in forward dynamics of multibody systems

It is known that the dynamic equations of motion for constrained mechanical multibody systems are frequently formulated using the Newton-Euler’s approach, which is augmented with the acceleration constraint equations. This formulation results in the establishment of a mixed set of partial differential and algebraic equations, which are solved in order to predict the dynamic behavior of general multibody systems. The classical resolution of the equations of motion is highly prone to constraints violation because the position and velocity constraint equations are not fulfilled. In this work, a general and comprehensive methodology to eliminate the constraints violation at the position and velocity levels is offered. The basic idea of the described approach is to add corrective terms to the position and velocity vectors with the intent to satisfy the corresponding kinematic constraint equations. These corrective terms are evaluated as function of the Moore-Penrose generalized inverse of the Jacobian matrix and of the kinematic constraint equations. The described methodology is embedded in the standard method to solve the equations of motion based on the technique of Lagrange multipliers. Finally, the effectiveness of the described methodology is demonstrated through the dynamic modeling and simulation of different planar and spatial multibody systems. The outcomes in terms of constraints violation at the position and velocity levels, conservation of the total energy and computational efficiency are analyzed and compared with those obtained with the standard Lagrange multipliers method, the Baumgarte stabilization method, the augmented Lagrangian formulation, the index-1 augmented Lagrangian and the coordinate partitioning method.The first author expresses his gratitude to the Portuguese Foundation for Science and Technology through the PhD grant (PD/BD/114154/2016). This work has been supported by the Portuguese Foundation for Science and Technology with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio

Uterotrema australispinosa n. gen., n. sp. (Digenea: Spirorchidae), a parasite of a freshwater turtle Emydura macquarii from Southern Queensland, Australia

Uterotrema australispinosa n. gen., n. sp. from the heart of the Murray River turtle Emydura macquarii (Pleurodira: Chelidae) is distinguished from other members of the Spirorchidae by the presence of a voluminous uterus; a single, lobed testis occupying the posterior quarter of the body; linear rows of 5-6 spines arranged along the lateral margins of the hindbody from the posterior rim of the acetabulum to the posterior end of the body; and the posterior end ventrally curved with a dorsal cluster of spines near the terminal end. This is the first report of a spirorchid from a member of the family Chelidae and from Australia

Description and life-cycle of two new species of Choanocotyle n. g. (Trematoda: Plagiorchiida), parasites of Australian freshwater turtles, and the erection of the family Choanocotylidae

A new genus, Choanocotyle, is proposed to include two plagiorchiidan species. Choanocotyle elegans n. sp. is described from the small intestine of the freshwater turtles Chelodina expansa and Emydura macquarii. Choanocotyle nematoides n. sp. is described from the large intestine of E. macquarri. Descriptions are given of the adult, egg and miracidium, cercaria and metacercaria of each species. The two species have similar three-host aquatic life-cycles. A planorbid snail, Glyptophysa gibbosa, served as first intermediate host for both species in the laboratory. Isidorella newcombi was found naturally infected with C. elegans. Eggs were fully embryonated and infective when laid, but did not hatch until eaten by G. gibbosa. The intramolluscan prepatent period was 50 days for C. elegans and 35 days for C. nematoides. Metacercariae of C. elegans were recovered from experimentally infected snails (G. gibbosa), tadpoles (Limnodynastes peronii) and naturally infected crayfish (Cherax sp.), while metacercariae of C. nematoides developed preferentially in the vertebral cartilage of L. peronii, but were also recovered from experimentally infected G. gibbosa, and field-collected leeches, Glossiphonia sp. Cercarial behaviour of each species is outlined briefly and observations are given on the host-parasite relationships of the metacercariae of each species. The disposition of Choanocotyle within the Plagiorchiida is discussed and it is concluded that it would be best placed in a new family, the Choanocotylidae