Bernal Morera

National University of Costa Rica | UNA · Escuela de Ciencias Biológicas

The rapid squirt of a proteinaceous slime jet endows velvet worms (Onychophora) with a unique mechanism for defence from predators and for capturing prey by entangling them in a disordered web that immobilizes their target. However, to date, neither qualitative nor quantitative descriptions have been provided for this unique adaptation. Here we inv...

Los onicóforos son considerados “fósiles vivientes” porque durante más de 500 millones de años su morfología ha cambiado muy poco y han mantenido un estadio evolutivo aparentemente intermedio entre los anélidos y los artrópodos. Aquí se analiza su biología, siguiendo la historia evolutiva del grupo desde el Cámbrico hasta el presente, con especial...

The general population of Costa Rica has sometimes been considered to be the product of an amalgamation of groups of diverse origin. To determine the magnitude of accumulated admixture since Spanish colonization, 11 classic genetic markers were analyzed in a total of 2196 individuals originating from five distinct regions of the country. A maximum...

En Costa Rica existen muy pocas investigaciones en el área de la enseñanza de la genética en secundaria, a pesar de la importancia que tiene esta disciplina actualmente, siendo base fundamental para otras áreas de las ciencias como las de la salud, las agrarias o ambientales. El propósito de este trabajo es analizar las técnicas utilizadas por dos...

Introduction: Neotropical onychophoran taxonomy and diversity has been poorly investigated. Recent studies have discovered problems in species classification: they have questioned the accepted genera and the actual number of species. This is true in Costa Rica, where several unidentified species have been reported. Objective: The objective of this...

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Introduction: Charismatic species, like the panda, play an important role in conservation, and velvet worms arguably are charismatic worms. Thanks to their extraordinary hunting mechanism, they have inspired from a female metal band in Japan, to origami worms in Russia and video game monsters in the USA. Objective: To assess their conservation stat...

Los onicóforos son el único filo sin representantes marinos actuales y uno de los pocos invertebrados con placenta. Acá proponemos que el antecesor común, el cual salió por primera vez a tierra firme en tiempos de Pangea, retenía sus huevos dentro del cuerpo materno, alimentándolos continuamente a través de una cáscara muy delgada (viviparismo matr...

Onychophorans are the only phylum without current marine representatives and one of the few invertebrates with placenta. Here we propose that the common ancestor, which first emerged to the mainland in Pangea's time, kept its eggs inside the female, feeding them continuously through a very thin shell (matrotrophic viviparity). Therefore, this mecha...

After more than a century of studying a phylum that has over 200 species, we only have three reports of the mating itself. Insemination can occur vaginally or through the skin, and it is suspected that the male simply places its genital opening against the vulva and inserts the spermatophore. However, in the particular case of a few Australian onyc...

Tras más de un siglo de estudio y a pesar de que hay más de 200 especies de onicóforos, solamente contamos con tres observaciones del apareamiento en sí. La inseminación se puede dar cuando el macho insemina vaginalmente o a través de la piel cuando los machos simplemente colocan su apertura genital contra la vulva y depositan el espermatóforo. En...

Los machos de algunos onicóforos australianos transfieren sus espermatóforos con estructuras espectaculares en la cabeza, como fosos con palpos y espinas. Nadie ha explicado por qué estas estructuras permiten identificar la especie. Acá proponemos que, cuando la cabeza hace de aparato genital, la selección natural la trata como aparato genital. Pro...

Males of some Australian onychophorans transfer their spermatophores with spectacular structures in their head, such as pits with palps and spines. No one has explained why these structures allow this species to be identified. Here we propose that, when its head is the genital apparatus, natural selection treats it as a genital apparatus. Probably...

The sperm of many onychophorans must cross body walls and swim for years before fertilizing an egg. We propose that the cause for such obstacles is the high cost of reproduction in these animals, which leads females to select eggs early in their development; and to invest heavily in their atypically large Golgi apparatus and in the production of gl...

Los espermatozoos de muchos onicóforos deben atravesar paredes corporales y nadar por años antes de poder fecundar un óvulo. Proponemos que la causa es el alto costo de la reproducción en estos animales, lo que lleva a las hembras a seleccionar tempranamente los óvulos, a invertir mucho en su aparato de Golgi atípicamente grande y en la producción...

In the only onychophorans mating that has been photographed, instead of fleeing, the couple remained together despite being manipulated. Why? The duration of copulation in onychophorans is possibly controlled by the female, larger and stronger than the male, probably with the participation of dopamine and γ-aminobutyric acid. Insemination through t...

En el único apareamiento de onicóforos que ha sido fotografiado, en lugar de huir, la pareja permaneció unida a pesar de que fue manipulada. ¿Por qué? La duración de la cópula en onicóforos posiblemente sea controlada por la hembra, más grande y fuerte que el macho, probablemente con la participación de dopamina y ácido γ-aminobutírico. La insemina...

One of the many mysteries surrounding onychophorans, is why, despite their small body size, they have gestation periods that are as long as gestation in some mammals. Here we propose that the causes are infrequent feeding and the Mandatory Minimum Size model, according to which they must be born sufficiently developed to hunt their own food and sur...

Hay dos maneras de ser un onicóforo. Una es aparearse vaginalmente a corta edad, dar a luz en cualquier mes y tener machos pequeños y escasos. La otra es inseminar periódicamente por la pared corporal, con igualdad sexual en tamaño y abundancia. La segunda manera parece ser una adaptación evolutiva que permite ocupar hábitats más fríos y secos que...

There are two ways to be a velvet worm. One is to mate vaginally at a young age, give birth in any month and have small, scarce males. The other is to periodically inseminate through the body wall, with sexual equality in size and abundance. The second way seems to be an evolutionary adaptation to habitats that are colder and drier than the habitat...

El viviparismo es tan ventajoso que ha evolucionado al menos 140 veces en los invertebrados, pero algunos onicóforos australianos y neozelandeses han retrocedido, abandonando el ovoviviparismo para volver a los huevos. ¿Por qué? Acá proponemos que es una adaptación a hábitats climáticamente inhóspitos y pobres en alimento.

Viviparity is so advantageous that it has evolved at least 140 times in the invertebrates, but some Australian and New Zealand onychophorans have gone back, abandoning ovoviviparity to return to laying eggs. Why? Here we propose that it is an adaptation to climatically inhospitable habitats and low food availability.

Uno de los muchos misterios que rodean a los onicóforos, es por qué, siendo tan pequeños, tienen períodos de gestación tan largos como algunos mamíferos. Acá proponemos que esto se debe a su alimentación infrecuente y al Modelo del Tamaño Mínimo Obligatorio, según el cual deben nacer ya suficientemente desarrollados para cazar su propio alimento y...

Charismatic species, like the panda, play an important role in conservation, and velvet worms arguably are charismatic worms. Thanks to their extraordinary hunting mechanism, they have inspired from a female metal band in Japan, to origami worms in Russia and video game monsters in the USA. Objective: To assess their conservation status in Costa Ri...

ABSTRACT: Charismatic species, like the panda, play an important role in conservation, and velvet worms arguably are charismatic worms. Thanks to their extraordinary hunting mechanism, they have inspired from a female metal band in Japan, to origami worms in Russia and video game monsters in the USA. Objective: To assess their conservation status i...

Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of hereditary peripheral neuropathies. We previously reported a CMT locus on chromosome 19q13.3 segregating with the disease in a large Costa Rican family with axonal neuropathy and autosomal recessive pattern of inheritance (CMT2B2). We proposed a homozygous missense variant in the...

Onychophorans or velvet worm are the only phylum without extant marine species and the only invertebrates with a true placenta, but most species are rare and thus more likely to become extinct. A key obstacle for their conservation is the time and work needed to describe species with the high standards of current taxonomy, and many species will rem...

Onychophoran worms are considered "living fossils" because their basic body structure has changed little in 500 million years. Only two species have been properly recorded from Mexico: Macroperipatus perrieri from Veracruz, and Oroperipatus eisenii from Nayarit. Here we report an undescribed species of Oroperipatus from Tuxtla Gutiérrez, Chiapas. M...

Onychophoran worms are considered "living fossils" because their basic body structure has changed little in 500 million years. Only two species have been properly recorded from Mexico: Macroperipatus perrieri from Veracruz, and Oroperipatus eisenii from Nayarit. Here we report an undescribed species of Oroperipatus from Tuxtla Gutiérrez, Chiapas. M...

Even though the Onychophora represent a whole phylum, observations of their activity pattern in nature are almost non-existent. Here we report on the relationship between humidity and light and activity pattern of a new species of velvet worm, genus Epiperipatus, from four years of field observations in the South Pacific of Costa Rica. We found tha...

Photographic evidence of undescribed species of velvet worms (Onychophora: Peripatidae) from Costa Rica. Onychophorans are hard to find and identify to species under field conditions. Currently, there are seven species described from Costa Rica, and an appropriate taxonomic revision is necessary. However, technology allows the documentation of rare...

Velvet worms, "peripatus" or onychophorans, are "living fossils" that were geographically widespread in Cambrian seas but now occur exclusively on terrestrial habitats. The only extant species studied in some detail are those from Costa Rica, but their real geographic distribution was in urgent need of revision. To solve this problem we visited the...

Onychophorans are hard to find and identify to species under field conditions. Currently, there are seven species described from Costa Rica, and an appropriate taxonomic revision is necessary. However, technology allows the documentation of rare and even undescribed species. Here we compile donated photographs and online images to identify 18 new C...

Velvet worms are rare invertebrates that currently live on land and look like fossils of the group found in what were marine mudflats in the Cambrian period. For a long time they were unknown to most people but we noticed that in the last decade they began to be mentioned in the Internet (in art websites and as illustrations in commercial products)...

The rapid squirt of a proteinaceous slime jet endows velvet worms (Onychophora) with a unique mechanism for defence from predators and for capturing prey by entangling them in a disordered web that immobilizes their target. However, to date, neither qualitative nor quantitative descriptions have been provided for this unique adaptation. Here we inv...

El objetivo del presente trabajo fue identificar especies de nematodos del género Meloidogyne asociadas a plantas ornamentales de altura. El estudio se realizó en el cantón de San Isidro de Heredia, Costa Rica, en un vivero comercial durante el periodo 2011-2012, en diez especies de plantas. Para la identificación se utilizaron mediciones morfométr...

Aims: To document and preserve folkloric beliefs and art inspired by velvet worms (Onychophora), rare invertebrates that are considered "living fossils", have full placental organs and capture prey with a rough "net" built in a fraction of a second. Study Design: This study is a combination of field interviews, online surveys and automatic database...

Worldwide there is an urgent need to monitor the conditions of monuments affected by biodeterioration and biodegradation, but no long term data exist for most of them. Here is an exception in the case of certain Roman monuments whose bioderioration and biodegradation agents were painted approximately 250 years ago by Giovanni Canal and Bernardo Bel...

Low character variation among onychophoran species has been an obstacle for taxonomic and phylogenetic studies in the past, however we have identified a number of new and informative characters using morphological, molecular, and chromosomal techniques. Our analyses involved a detailed examination of Epiperipatus biolleyi from Costa Rica, Eoperipat...

Supplementary file containing the following figures and tables.: Figure S1. Eversible coxal vesicles (arrowheads). (A) Principapillatus hitoyensis gen. et. sp. nov. Light micrograph of ventral leg surface. (B) Eoperipatus sp.. Scanning electron micrograph of ventral leg surface. Anterior is right in both images. Figure S2. Additional features of Pr...

The technological advances in Genetics have given rise to the science of Molecular Genealogy, by giving us the opportunity to approach the study of pedigrees from a new perspective, examining alive people at the same time than collating records from their ancestors. A four generations matrilineal genealogy is presented from Da. Angela Antunez (b. a...

Traditionally the Costa Rican historians and genealogists have interpreted that the Spanish ruling elite emerged after the conquest was exclusively of European origin. On the other side, recent technological advances in Genetics give us the opportunity to approach the study of pedigrees from a new perspective, examining alive people and simultaneou...

NOTA: Semi-aquatic turtles often dive to escape from terrestrial predators, but to our knowledge, the time that Costa Rican species can stay under water is unknown. To obtain preliminary measurements of this ecologically significant parameter, we tested several individuals in an aquarium with water at 25°C in Sabanilla, San José, Costa Rica. We p...

Meloidogyne es un nematodo endoparásito sedentario de amplia distribución geográfica, responsable de causar pérdidas económicas cuantiosas en una amplia variedad de cultivos. La globalización y la apertura de mercados para la importación y exportación de plantas ornamentales probablemente ha contribuido a la introducción de nuevas especies, las cua...

Onychophorans, or velvet worms, are poorly known and rare animals. Here we report the discovery of a new species that is also the largest onychophoran found so far, a 22 cm long female from the Caribbean coastal forest of Costa Rica. Specimens were examined with Scanning Electron Microscopy; Peripatus solorzanoi sp. nov., is diagnosed as follows: p...

Haemophilia is the most frequent hereditary haemorrhagic illness and it is due to the deficiency of coagulation factors VIII (haemophilia A, HA) or IX (haemophilia B, HB). The prevalence of this disease varies according to the country, those having better survival rates having also higher prevalences. Specifically in Costa Rica, there are around 13...

During long time, historians and genealogists have interpreted that the elite that emerged during the Spanish Conquest was almost exclusively European. We reconstructed a deep matrilineal genealogy which includes recent Costa Rican ex-presidents and religious authorities back to their ancestors at the early 17th century, and compared their historic...

The genealogy of Maria de Aguilar: evidence of admixture in the early Spanish Colony in Costa Rica. During long time, historians and genealogists have interpreted that the elite that emerged during the Spanish Conquest was almost exclusively European. We reconstructed a deep matrilineal genealogy which includes recent Costa Rican ex-presidents and...

Charcot-Marie-Tooth (CMT) disease is a clinically and genetically heterogeneous disorder. All mendelian patterns of inheritance have been described. We identified a homozygous p.A335V mutation in the MED25 gene in an extended Costa Rican family with autosomal recessively inherited Charcot-Marie-Tooth neuropathy linked to the CMT2B2 locus in chromos...

To describe the clinical, electrophysiologic and morphologic features of a Costa Rican family with an autosomal dominant inherited Charcot-Marie-Tooth (CMT) neuropathy. The field study took place in Costa Rica, Central America. Seven patients underwent neurological examinations and standard electrodiagnostic tests, and a sural nerve biopsy was take...

Las poblaciones generales de los países de Centro América son consideradas genealógica, histórica y tradicionalmente como producto del mestizaje de europeos, amerindios y algunas veces de africanos. Durante los últimos años se han venido realizando una serie de estudios que pretenden desentrañar la estructura genética de estas poblaciones con propó...

The DNA technology has become a powerful tool for human identification in the last few years even in cases where the bones are the only remains. We now report the successful identification of the skeletal remains of a murder victim by comparative typing on nuclear DNA in remains, and in the presumptive parents of the victim. The genetic markers use...

The population of Nicaragua has been traditional and historically considered to be the product of admixture. To determine the magnitude of accumulated admixture, there were analyzed 100 Nicaraguans originating from different localities of the country. A total of 6 PCR-derived loci were evaluated. Admixture components were estimated by the gene iden...

Charcot-Marie-Tooth disease (CMT) comprises a group of frequent, genetically and clinically heterogenous peripheral neuropathies. Two main CMT forms are distinguished: the demyelinating CMT type 1 (CMT1) and the axonal CMT type 2 (CMT2). Recently, we reported linkage of the axonally pronounced CMT2B2 type to chromosome 19q13.3 (OMIM %605589). Analy...

In the last decade, the Costa Rican Central Valley population (CRCV), has received considerable scientific attention, attributed in part to a particularly interesting population structure. Two different and contradictory explanations have emerged: (1) An European-Amerindian-African admixed population, with some regional genetic heterocigosity and m...

La reciente utilización de la tecnología del ADN para la identificación individual a traído consigo una revolución en las ciencias forenses, que ha alcanzado también a la America Latina. El análisis histórico muestra que en Costa Rica se han logrado importantes avances y en la actualidad se encuentra consolidado el trabajo con los STRs, y se están...

Complete electronic DNA profiles of 2006 randomly selected Costa Ricans, typed for 7 PCR-based loci, are presented. Such data may prove valuable for anthropological and forensic studies of the Costa Rican population. Rev. Biol. Trop. 52(3): 713-715. Epub 2004 Dic 15.Se presenta una versión electrónica de los perfiles genéticos completos de 2006 ind...

Charcot-Marie-Tooth disease (CMT) comprises a heterogeneous group of hereditary motor and sensory peripheral neuropathies. The autosomal recessive axonal form of CMT (ARCMT2) is rare. Eight patients of a large consanguineous family of Spanish ancestry in Costa Rica were diagnosed with ARCMT2B; previous genetic studies of this family revealed linkag...

A survey was distributed by e-mail to 553 biologists who study the Neotropics, in order to identify the journals, books and researchers with the greatest influence over Latin American biology. The biologists' database of the Revista de Biología Tropical was used to obtain their addresses. One third of them answered. The Revista de Biología Tropical...

A survey was distributed by e-mail to 553 biologists who study the Neotropics, in order to identify the journals, books and researchers with the greatest influence over Latin American biology. The biologists' database of the Revista de Biología Tropical was used to obtain their addresses. One third of them answered. The Revista de Biología Tropical...

Tainos and Caribs were the inhabitants of the Caribbean when Columbus reached the Americas; both human groups became extinct soon after contact, decimated by the Spaniards and the diseases they brought. Samples belonging to pre-Columbian Taino Indians from the La Caleta site (Dominican Republic) have been analyzed, in order to ascertain the genetic...

A re-analysis of recently published mtDNA sequences for HVR1 and HVR2 in 90 individual from the Costa Rican population suggest the existence of errors and inconsistencies in published data, of diferences between published data and their description and biases that lead to a population that is less variable and less informative than previously descr...

A study of several loci blood groups (ABO, Diego, Duffy, Kell, Kidd, Lewis, Lutheran, MNSs, P, Rhesus and Secretor), and Hp serum protein was carried out on a sample of 2 196 unrelated Costa Rican individuals of both sexes. Data was classified and analyzed according to geographic regions. Gene frequencies and the goodness of fit to Hardy-Weinberg e...

A study of several loci blood groups (ABO, Diego, Duffy, Kell, Kidd, Lewis, Lutheran, MNSs, P, Rhesus and Secretor), and Hp serum protein was carried out on a sample of 2,196 unrelated Costa Rican individuals of both sexes. Data was classified and analyzed according to geographic regions. Gene frequencies and the goodness of fit to Hardy-Weinberg e...

Nicaraguans have become the most numerous and fastest increasing minority in Costa Rica: at present they represent around 6% of the total population of the country. We have analyzed the allele and genotype frequencies of six PCR-based genetic markers (LDLR, GYPA, HBGG, D7S8, GC, and HLA-DQA1) in 100 unrelated Nicaraguans living in Costa Rica. All l...

Tainos and Caribs were the inhabitants of the Caribbean when Columbus reached the Americas; both human groups became extinct soon after contact, decimated by the Spaniards and the diseases they brought. Samples belonging to pre-Columbian Taino Indians from the La Caleta site (Dominican Republic) have been analyzed, in order to ascertain the genetic...

Autosomal recessive Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of disorders affecting the peripheral nervous system. The axonal form of the disease is designated as "CMT type 2" (CMT2), and one locus (1q21.2-q21.3) has been reported for the autosomal recessive form. Here we report the results of a genomewide search in an inb...

Charcot-Marie-Tooth (CMT), a group of hereditary motor-sensory neuropathies, is a clinical and genetically heterogenous disorder of the peripheral nervous system. Recently, we found linkage in a Costa Rican family with autosomal recessive CMT type 2 (ARCMT2B) in chromosome 19q13.3. The critical interval was defined between markers D19S902 and D19S9...

We have analysed a large set of autosomal short tandem repeat (STR) loci in several Arabic and Berber-speaking groups from north-west Africa (ie Moroccan Arabs, northern-central and southern Moroccan Berbers, Saharawis, and Mozabites). Two levels of analysis have been devised using two sets of 12STR loci, (D3S1358, vWA, FGA, THO1, TPOX, CSF1PO, D8S...

Anécdota sobre la historia de la llegada de Juan Gätjens a Costa Rica.

We have analysed a large set of autosomal short tandem repeat (STR) loci in several Arabic and Berber-speaking groups from north-west Africa (ie Moroccan Arabs, northern-central and southern Moroccan Berbers, Saharawis, and Mozabites). Two levels of analysis have been devised using two sets of 12STR loci, (D3S1358, vWA, FGA, THO1, TPOX, CSF1PO, D8S...

The genealogy of Maria de Aguilar: evidence of admixture in the early Spanish Colony in Costa Rica. During long time, historians and genealogists have interpreted that the elite that emerged during the Spanish Conquest was almost exclusively European. We reconstructed a deep matrilineal genealogy which includes recent Costa Rican ex-presidents and...

Forensic implementation of DNA technology in Costa Rica: a retrospective analysis. La reciente utilización de la tecnología del ADN para la identificación individual a traído consigo una revolución en las ciencias forenses, que ha alcanzado también a la América Latina. El análisis histórico muestra que en Costa Rica se han logrado importantes avan...

Los huesos antiguos son una buena fuente de ADN, útil en muchos casos para el análisis forense, especialmente cuando el tejido blando está severamente descompuesto o dañado. Existen diferentes métodos para la extracción de ADN a partir de restos óseos, con diferentes eficacias, y que plantean varios problemas técnicos. Se presenta una revisión bibl...

The DNA technology has become a powerful tool for human identification in the last few years even in cases where the bones are the only remains. We now report the successful identification of the skeletal remains of a murder victim by comparative typing on nuclear DNA in remains, and in the presumptive parents of the victim. The genetic markers use...