Saurochory in crocodiles does not favor seed dispersai and viability / Saurocoría en cocodrilos no favorece la dispersión y la viabilidad de semillas

RESUMEN La dispersión de semillas por reptiles (saurocoría) ha recibido atención recientemente y se ha reportado el consumo de frutos y semillas en cocodrilianos, actuando como potenciales dispersores de semillas. Evaluamos si la saurocoría en Crocodylus actus y C. moreletii afecta la viabilidad de tres especies de plantas Delonixregia, Inga sp. y Citrullus lanatus. Se Utilizaron tres individuos juveniles de cada especie de cocodrilo y se alimentaron con 22 semillas por especie de planta, para un total de 66 semillas por recinto (132 para ambos). Las semillas se mezclaron con la dieta habitual cada semana, las semillas no consumidas y las excretadas se recolectaron y sembraron en suelo tratado con composta para evaluar la tasa de germinación relativa. Un total de 99 semillas fueron consumidas pero solo se recuperaron de las heces 14 semillas de C. lanatus, y germinando solo una de ellas (7, 14 %) con respecto al 50 % en el grupo control. Los resultados indican que la saurocoría de C. acutus y C. moreletii tiene un efecto negativo sobre la viabilidad de las semillas de las especies vegetales estudiadas, concordando con otros estudios realizados en diferentes especies.

ABSTRACT Seed dispersal by reptiles (saurochory) has recently received attention, and the consumption of fruits and seeds has been reported in crocodilians despite being mainly carnivores, acting as potential seed dispersers. We evaluate whether saurochory by Crocodylus acutus and C. moreletii affect the seed viability of three species of plants (Delonix regia, Inga sp., and Citrullus lanatus). We performed feeding trials, using three juvenile individuals of each species of crocodile, and fed them 22 seeds per plant species for a total of 66 seeds per enclosure (132 for both species). Seeds were combined with the usual diet each week. The unconsumed and excreted seeds were collected and planted in soil treated with compost to evaluate the relative germination rate. A total of 99 seeds were consumed, of which only 14 seeds of C. lanatus were recovered from the faeces, and only one of those germinated (7.14 %) with respect to 50 % in the control group. The results indicate that saurochory by C. acutus and C. moreletii has a negative effect on seed viability and germination of the plant species studied, as found in other studies using different species.

Is Surgery for Hepatic Echinococcosis Appropriate in a Low-Volume Center?

Background: Cystic echinococcosis is a parasitic disease that develops in endemic areas due to the transmission of Echinococcus granulosus. The liver is the organ most affected. The most frequent symptoms include pain, palpable mass, jaundice, and fever. Diagnosis is based on epidemiologic history, examination, imaging, and serologic tests. Patients and Methods: We conducted a retrospective study of patients with hepatic echinococcosis diagnosed in our center. We collected data from our patients regarding personal history, cyst characteristics, surgery performed, and post-operative complications. Results: Sixteen patients were diagnosed with hepatic echinococcosis, 11 of whom underwent surgery. We found multiple cysts in six patients (37.5%) and a single cyst in 10 (62.5%). In 14 patients the cysts were found only in the right hepatic lobe (87.5%) and in two patients they were found in both lobes (12.5%). Segment 4 was affected in seven cases. The sizes ranged from 2.7 to 20 cm. Endoscopic retrograde cholangiopancreatography was prior to surgery in five patients. The interventions performed were partial cyst-pericystectomies in eight patients, a total cyst-pericystectomy in one case, and drains were placed in two cases of rupture. Post-operative fistulas were evident in five patients, four of which were closed. The fifth, which occurred after emergency surgery for rupture of the cyst, has maintained suppuration. The mean follow-up was 3.5 years. There was no post-operative mortality or recurrence to date. Conclusions: We can state that center without highly specialized hepato-biliary surgery units can assume the surgery of hydatid liver cysts excluding those with well-defined characteristics. The establishment of recommendations for the referral of patients with complex hydatid cysts may help in the optimal management of this pathology.

A new species of leaf-toed gecko (Phyllodactylidae, Phyllodactylus) from María Cleofas Island, Nayarit, Mexico.

We describe a new species of leaf-toed gecko of the genus Phyllodactylus from María Cleofas Island, the smallest island of Tres Marías Archipelago, Nayarit, México. Genomic, phylogenomic, and morphological evidence support that the new species presents a unique combination of diagnostic characters. Morphologically, the new species has a high number of tubercles, head to tail (mean 47), longitudinal ventral scales (mean 61), and third labial-snout scales (mean 26). Gene flow tests revealed the genetic isolation of insular populations from mainland counterparts. In addition, we confirmed the non-monophyly of P. homolepidurus and P. nolascoensis, and we show that the taxon P. t. saxatilis is a complex; therefore, we propose taxonomic changes within the saxatilis clade. The discovery of this new insular endemic species highlights the urgency of continued exploration of the biological diversity of island faunas of Mexico.

AMPLIACIÓN DEL ÁMBITO GEOGRÁFICO Y DE LA TALLA MÁXIMA DE Kinosternon chimalhuaca (TESTUDINES: KINOSTERNIDAE) / Extension of geographic range and maximun size of Kinosternon chimalhuaca (Testudines: Kinosternidae)

RESUMEN Kinosternon chimalhuaca (Casquito de Jalisco) es una tortuga kinosternida endémica de México. La talla máxima de longitud de caparazón (CL) es de 160 mm en machos y de 130 mm en hembras. Tiene un pequeño rango de distribución en la costa del Pacífico de Jalisco y Colima (México), desde el río Tuito en Jalisco hasta el río Cihuatlán en el noroeste de Colima. Este nuevo registro en Puerto Vallarta, Jalisco, extiende su distribución al menos 32 km al norte de la localidad más septentrional conocida. Se registra un nuevo tamaño máximo (CL) para la especie de 172,00 mm (un macho).

ABSTRACT Kinosternon chimalhuaca (Jalisco Mud Turtle) is a kinosternid turtle endemic to Mexico. The previously recorded maximun carapace length (CL) is 160 mm in males and 130 mm in females. It has a small distribution range along the Pacific coast of Jalisco and Colima, Mexico, from the rio Tuito in Jalisco to the rio Cihuatlán in northwestern Colima. This new record in Puerto Vallarta, Jalisco, extends its distribution at least 32 km north from the northernmost known locality. A new maximun size (CL) for the species of 172.00 mm (one male) is recorded.

Nest-site selection and nest size influence the incubation temperature of Morelet's crocodiles.

In oviparous tetrapods, the nesting-site selection by females is related to the habitat characteristics, which influences nest incubation temperature. Females can directly influence the incubation temperature by choosing certain construction materials or by building nests of different sizes. There are few studies focusing on these aspects in crocodilians that build mound nests. The aim of this study was to determine whether the nest size, its exposure to solar radiation, and the environmental temperature influence the incubation temperature of Morelet's crocodile (Crocodylus moreletii) nests. Artificial nests of two sizes (small and large) were constructed with similar characteristics to natural nests and placed in two locations differing in exposure to solar radiation (shaded and sunny). We used temperature and relative humidity data loggers to record the incubation temperature inside each nest every hour during the species' natural nesting period. Likewise, we recorded the ambient temperature every hour where the experiments were set up with temperature data loggers. We found that nest size and its exposure to solar radiation affected the incubation temperature, with smaller nests in shaded locations having lower incubation temperatures than larger nests in sunny locations. We discuss the importance of nest-site selection and maintenance behaviour of the mound nest by female crocodiles on the incubation temperature of the nest.

Thermal fluctuation within nests and predicted sex ratio of Morelet's Crocodile.

Understanding the interplay between thermal variations and sex ratio in reptiles with temperature-dependent sex determination is the first step for developing long-term conservation strategies. In case of crocodilians, the information is fragmentary and insufficient for establishing a general framework to consider how thermal fluctuation influence sex determination under natural conditions. The main goal of this study was to analyze thermal variation in nests of Crocodylus moreletii and to discuss the potential implications for predicting offspring sex ratio. The study was carried out at the Centro de Estudios Tecnológicos del Mar N° 2 and at the Sistemas Productivos Cocodrilo, Campeche, Mexico. Data was collected in the nesting season of Morelet's Crocodiles during three consecutive seasons (2007-2009). Thermal fluctuations for multiple areas of the nest chamber were registered by data loggers. We calculate the constant temperature equivalent based on thermal profiles among nests to assess whether there are differences between the nest temperature and its equivalent to constant temperature. We observed that mean nest temperature was only different among nests, while daily thermal fluctuations vary depending on the depth position within the nest chamber, years and nests. The constant temperature equivalent was different among and within nests, but not among survey years. We observed differences between constant temperature equivalent and mean nest temperature both at the top and in the middle of the nest cavities, but were not significantly different at the bottom of nest cavities. Our results enable examine and discuss the relevance of daily thermal fluctuations to predict sex ratio of the Morelet's Crocodile.

Morphometric analysis of the Rio Apaporis Caiman (Reptilia, Crocodylia, Alligatoridae).

Caiman crocodilus apaporiensis has been considered by several authors as an extreme of morphological variation within the Caiman crocodilus complex. Here, we evaluate its position in the Caiman crocodilus complex morphospace using morphological traits from head shape. We examined the holotype and seventeen paratypes of Caiman crocodilus apaporiensis Medem 1955 deposited at the Field Museum of Natural History. We performed multivariate morphometric analyses: principal component analysis (PCA) and discriminant function analysis (DFA), based on 21 cranial traits of of C. c. apaporiensis, C. yacare and the C. crocodilus complex (C. c. chiapasius, C. c. fuscus andC. c. crocodilus). We find a notable separation of C.c. apaporiensis from C. yacare and C. crocodilus complex in the morphospace. We suggest that geographic isolation might have driven this morphological separation from the C. crocodilus complex, but further analysis are necessary to confirm whether these differences are related with genetic differentiation within the complex. In addition, we suggest that environmental heterogeneity might drive the evolution of independent lineages within the C. crocodilus complex.

Sexual size dimorphism and allometric growth of Morelet's crocodiles in captivity.

Few studies have conducted morphological analyses of crocodilians, and little information exists on differences between size-classes and sexes in Neotropical crocodilians. In this study, we measured nine morphological traits in 121 captive Morelet's crocodiles Crocodylus moreletii (81 females and 40 males). Our results revealed that individuals < 2 m total length do not exhibit sexual dimorphism in morphometric characteristics. However, for crocodiles over 2 m in length, males were significantly larger than females in terms of dorsal-cranial length, cranial width, snout width and snout-ventral length. In general, morphological traits demonstrated a strongly significant relationship with total length at the smaller size class of 150-200 cm length. However, in the highest size class of 250-300 cm length (large adult males), morphological traits were no longer significantly related with total length. Male crocodiles demonstrated allometric growth of cranial morphology with significantly greater increase in cranial width, snout width, and mid-snout width relative to total length at higher size classes. Morphological dimorphism and allometric growth may be associated with adaptive strategies for reproductive success.

Mitochondrial DNA phylogeography of Caiman crocodilus in Mesoamerica and South America.

The Neotropical crocodylian species, Caiman crocodilus, is widely distributed through Mesoamerica, northern South America, and the Amazon basin. Four subspecies are recognized within C. crocodilus, suggesting some geographic variation in morphology. In this study, we utilized mitochondrial DNA (mtDNA) sequence data from 45 individuals of C. crocodilus throughout its range to infer its evolutionary history and population structure, as well as to evaluate genealogical support for subspecies and their geographic distributions. Our molecular phylogenetic results identified five mtDNA haplotype clades with a mean sequence divergence of 3.4%, indicating considerable evolutionary independence among phylogeographic lineages. Our results were also broadly consistent with current subspecific taxonomy, with some important additional findings. First, we found substantial genetic structuring within C. c. fuscus from southern Mesoamerica. Second, though we confirmed the existence of a widespread Amazonian clade, we also discovered a cryptic and divergent mtDNA lineage that was indistinguishable from C. c. crocodilus based on external morphology. Third, we confirm the status of C. c. chiapasius as a distinct evolutionary lineage, and provide evidence that C. c. fuscus may be moving northward and hybridizing with C. c. chiapasius in northern Mesoamerica. Finally, our results parallel previous phylogeographic studies of other organisms that have demonstrated significant genetic structure over shorter geographic distances in Mesoamerica compared with Amazonia. We support conservation efforts for all five independent lineages within C. crocodilus, and highlight the subspecies C. c. chiapasius as a unit of particular conservation concern.

Crecimiento en cautiverio de Crocodylus acutus (Cuvier, 1807) en Tumbes, Perú / Growth in captivity of Crocodylus acutus (Cuvier, 1807) in Tumbes, Peru

Se evaluó el crecimiento en peso y longitud en 40 individuos del Cocodrilo de Tumbes en el Centro de Acuicultura La Tuna Carranza, localizado en Puerto Pizarro, Departamento de Tumbes. No se observó una diferencia en el incremento en longitud por clases de edad, mientras que en peso si presentaron diferencias siendo mayor en adultos. El crecimiento promedio de longitud y peso fue de 1,44% y 0,18% en crías, 1,30% y 0,10% en reclutas, 1,24 y 0,22% en juveniles, 1,24 y 0,48% en subadultos, y 1,01 y 0,75% en adultos. En general las hembras presentan un mayor crecimiento que los machos.

A group of 40 individuals of C. acutus by captive reproduction maintained in the Centro de Acuicultura La Tuna Carranza, localed en Puerto Pizarro, Departamento de Tumbes was used to evaluate the growth. Comparations between size class of crocodiles showed that growth in length are not different, but growth in weight are different. The mean growth in length and weight was 1,44% and 0,18% in hatchling, 1,30 and 0,10% in yearlings, 1,24 and 0,22% in juveniles, 1,24 and 0,48% in subadults, and 1,01 and 0,75% in adults. The growth rate of females was highest that males.

Manejo de la displasia del desarrollo de la cadera en el periodo ambulatorio / Treatment of developmental dysplasia of the hip in the ambulatory age

A través de los años numerosos autores han hecho énfasis en la detección temprana de la displasia del desarrollo de la cadera (DDC), sin embargo, sigue existiendo un alto porcentaje de casos diagnosticados en la etapa de inicio de la deambulación, momento en que ya se encuentran establecidos cambios adaptativos como displasia acetabular, anteversión y valgo femoral; habiéndose perdido el periodo de "oro" del niño con capacidad de remodelación de la cadera displásica. En el periodo comprendido entre 1972 y 1990, se registraron en el Hospital Shriner's para Niños Lisiados, Unidad de México, 638 casos de DDC; para nuestra revisión se excluyeron los casos asociados a otras malformaciones congénitas y los casos inveterados, contando con 338 pacientes diagnosticados y tratados entre el periodo neonatal y los 3 años de edad, sin embargo el objetivo de nuestro estudio es la evaluación de los casos tratados en el periodo ambulatorio por lo que nos quedamos con 210 pacientes con 264 caderas con displasia del desarrollo. Dividimos nuestros casos en 4 grupos: Grupo I, 96 caderas tratadas sólo con reducción abierta; Grupo II, 129 caderas, tratadas mediante reducción abierta y osteotomía del iliaco; Grupo III, 11 caderas (4.1 por ciento), tratadas con reducción abierta y osteotomía femoral y Grupo IV, 28 caderas (10.6 por ciento), tratadas mediante un solo procedimiento quirúrgico combinando reducción abierta y osteotomía femoral y del iliaco. Los resultados fueron evaluados de acuerdo a los criterios clínicos de Barret y radiológicos de Severin. En cada uno de los grupos se encontraron caderas que requirieron de una segunda o tercera intervención quirúrgica debido a la presencia de deformidades residuales o persistentes, por lo que evaluamos los mismos grupos después del primer y último tratamiento. Al momento de la primera evaluación, los mejores resultados se encontraron en el grupo IV, y un alto porcentaje de resultados regulares y malos o pobres en los grupos I, II y III, debido a la persistencia o recidiva de la luxación; en la evaluación final encontramos disminución de los resultados malos o pobres al haber corregido deformidades residuales o persistentes. Por lo tanto, creemos que un sólo procedimiento quirúrgico combinado es el mejor tratamiento para un complejo patológico ya establecido y acentuado en la etapa ambulatoria sin necesidad de someter al niño a múltiples intervenciones quirúrgicas, retrasando además el periodo de rehabilitación.

Osteotomía de Chiari / Chiari iliac osteotomy

Se presenta una serie de 48 pacientes con caderas inestables y/o dolorosas por deficiencia cetabular que fueron tratados con acetabuloplastía de Chiari en el Hospital Shriners para Niños Lisiados, Unidad de la Ciudad de México de 1977 a 1990; con un seguimiento promedio de 3.1 años. La edad al momento de la cirugía fue de 12.8 años en promedio. Los parámetros clínicos evaluados fueron movilidad de la cadera, marcha, fuerza muscular, signo de Trendelenburg, dolor y acortamiento, dándole dos puntos a cada parámetro. En cuanto a los resultados; la movilidad de la cadera, la fuerza muscular, la marcha y el Trendelenburg mejoraron en la mayoría de los pacientes, el dolor aumentó en dos pacientes y el resto están asintomáticos. Concluimos que la osteostomía de iliaco de Chiari debe considerarse como procedimiento electivo para caderas inestables y/o dolorosas con insuficiencia acetabular para dar mejor estabilidad y cobertura de la cabeza femoral, y así mejorar la biomecánica de la cadera

Anormalidades congénitas del fémur / Congenital absence of the radius

Los pacientes con anormalilades congénitas del fémur presentan múltiples problemas que difícilmente son vistos por un cirujano ortopedista en forma individual. En este estudio se analizan el tratamiento de 62 anomalías congénitas del fémur en 60 pacientes, tratados en el Hospital Shriner para Niños Lisiados, de la Ciudad de México, en el periodo comprendido entre enero de 1982 y diciembre de 1991. Para todos los pacientes se utilizó la clasificación de Pappas. Los pacientes de la clase I a la VI se identifican al nacimiento, y todos requieren de tratamiento protésico. Los pacientes de las clases VII a la IX se deben evaluar en forma individual y decidir cuáles son candidatos para igualar la longitud de las extremidades. Independientemente de la clasificación se debe individualizar el tratamiento; esto depende de las malformaciones asociadas en la extremidad pélvica (hemimelia paraxial longitudinal, hipoplasia tibial y/o peronea, etc.)