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, Eoperipatus sp. from Thailand, and a new onychophoran species and genus from Costa Rica, Principapillatus hitoyensis gen. et sp. nov.. Scanning electron microscopy on embryos and specimens of varying age revealed novel morphological characters and character states, including the distribution of different receptor types along the antennae, the arrangement and form of papillae on the head, body and legs, the presence and shape of interpedal structures and fields of modified scales on the ventral body surface, the arrangement of lips around the mouth, the number, position and structure of crural tubercles and anal gland openings, and the presence and shape of embryonic foot projections. Karyotypic analyses revealed differences in the number and size of chromosomes among the species studied. The results of our phylogenetic analyses using mitochondrial COI and 12S rRNA gene sequences are in line with morphological and karyotype data. However, our data show a large number of unexplored, albeit informative, characters in the Peripatidae. We suggest that analysing these characters in additional species would help unravel species diversity and phylogeny in the Onychophora, and that inconsistencies among most diagnostic features used for the peripatid genera in the literature could be addressed by identifying a suite of characters common to all peripatids.

A cladistic analysis places the Onychophora between Polychaeta and Arthropoda. The ‘Uniramia‘concept is not supported. No justification was found for either onychophoran family to be considered ancestral. A cladogram of fossil genera indicates the common ancestor to have long oncopods, armoured plates and an annulated body. Later forms show adaptations to life in reduced spaces. Physiological data suggest that the Onychophora became adapted to land via the littoral zone, before the Late Ordovician. Adhesive glands evolved for defence on land. Peripatopsidae and Peripatidae were distinct by the late Triassic. The occurrence of onychophorans probably dates from post‐Pliocene in New Guinea and southern Australia, and post‐Early Cretaceous in Chile, the southern half of Southeast Asia, Mesoamerica and the Caribbean. After the Early Cretaceous, the peripatids of tropical Africa lost terrestrial contact with those of South America. A new biogeographic technique, formalized here under the name retrovicariance, indicates that the Peripatidae of Equatorial Africa and the Neotropics are sister‐groups. Typical inbreeding adaptations found in some onychophorans include: female‐biased sex ratios; gregarious development; relatively constant time of development and number of offspring in each clutch; male polygamy and shorter life span; frequent sibmating in the microhabitat of development, and sperm storage by females, so that a single insemination fertilizes all ova.

SUMMARY This review covers previous data, together with new information from our laboratories, on the subject of the anthocerote chloroplast. Unlike all other archegoniates, most species of anthocerote have pyrenoids in their chloroplasts. The pyrenoid is the site of accumulation of the first enzyme in the C3 photosynthetic cycle, ribulose bispbosphate carboxylase/oxygenase. Unlike most algae, the hornwort pyrenoid is composed of distinct subunits, numbering up to several hundred. Pyrenoid morphology is quite variable among the genera in shape, fine structure, and distribution of inclusions. Another unique feature of the anthocerote chloroplast is the presence of thylakoids that connect adjacent granal stacks at right angles to the long axis of the granum (so‐called channel thylakoids), resulting in a 'spongy’arrangement of the thylakoid system. The granal stacks of anthocerotes are like the‘pseudograna’of green algae because they lack the highly‐curved end membranes typical of all other embryophytes. The channel thylakoids are enriched in photosystem (PS) I and the grana are enriched in PS II. The chloroplast envelope is a double membrane structure with regions of appression, much like that of other green plants. The apieal cell of the gametophyte contains chloroplasts similar to the mature chloroplasts of the thallus, although certain gametophytic tissues may contain underdeveloped plastids. Chloroplasts in cells around Nostoc colonies and in cells invaded by mycorrhizal fungi have thylakoids mainly in pairs, and small or absent pyrenoids. A number of similarly reduced plastids are noted in the placental cells at the sporophyte/gametophyte junction and in developing spores. The greatest reduction is observed in spermatid cell plastids, which at maturity consist of only a small starch grain surrounded by the envelope. Chromoplast‐like organelles are found in the cells of the antheridial jacket in some genera; these contain numerous osmiophilic globules that are probably pigment aggregations. Colourless bead‐like plastids occur in the rhizoids; these seem to develop by fragmentation of the single chloroplast in the rhizoid initials, concomitant with the loss of chlorophyll. Chloroplast division is a tightly controlled process and, in uniplastidic species, always occurs just before nuclear division, with the participation of a unique system of chloroplast‐associated microtubules. The number of chloroplasts per cell is quite variable in some genera, although most species have but a single chloroplast in each cell of the gametophyte. Chloroplast shape is also variable from ellipsoidal, dumbbell‐shaped, to irregular. These data indicate that the anthocerote chloroplast is unique among the embryophytes and are in line with the notion of an isolated position in the plant kingdom. Certain features of chloroplast morphology appear to be typical of certain genera and might prove useful in taxonomic decisions at the generic level.

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 investigate the fast oscillatory motion of the oral papillae and the exiting liquid jet that oscillates with frequencies f~30–60 Hz. Using anatomical images, high-speed videography, theoretical analysis and a physical simulacrum, we show that this fast oscillatory motion is the result of an elastohydrodynamic instability driven by the interplay between the elasticity of oral papillae and the fast unsteady flow during squirting. Our results demonstrate how passive strategies can be cleverly harnessed by organisms, while suggesting future oscillating microfluidic devices, as well as novel ways for micro and nanofibre production using bioinspired strategies.

Despite of its small size, the Central American country of Costa Rica is internationally recognized as one of the world leaders in conservation and as the Central American leader in science. There have been no recent studies on the country's scientific production. The objective of this study was to analyze the Costa Rican scientific output as represented in the Science Citation Index Expanded. All documents with "Costa Rica" in the address field from 1981 to 2010 were included (total 6 801 publications). Articles (79%) were more frequent than other types of publication and were mostly in English (83%). Revista de Biología Tropical published the most articles (17%), followed by Toxicon and Turrialba (2.5%). The New England Journal of Medicine had the highest impact factor (53.484) with nine articles. Of 5 343 articles with known institutional address, 63%were internationally collaborative articles (most with the USA) with h index 91 and citation per publication 18. A total of 81% of all articles were inter-institutionally collaborative articles, led by the Universidad de Costa Rica. This reflects research and education agreements among these countries. Universidad de Costa Rica ranked top one in inter-institutionally collaborative articles, the rank of the total inter-institutionally collaborative articles, and the rank of first author articles and corresponding author articles. Studied subjects and journals in our sample are in agreement with dominant science fields and journals in Costa Rica. Articles with the highest citation were published in New England Journal of Medicine. The largest citation of medical articles reflects the general interest and wider readership of this subject. All corresponding and first authors of the high impact articles were not from Costa Rica. In conclusion, the scientific output of Costa Rican authors is strong in the areas related to conservation but the impact is higher for biomedical articles, and Costa Rican authors need to improve their position within research teams.

Panama is a small Central American country for which apparently there are no specific scientometric studies. We analyzed 4 854 research documents originating in Panama in the Science Citation Index Expanded (SCI-EXPANDED). Most are formal articles and nearly all are in English. The main fields are ecology, botany, zoology, evolution and aquatic biology. Most collaboration is done with USA, Germany, United Kingdom, Canada, and Brazil and the largest numbers of articles are published by the Smithsonian Tropical Research Institute, the University of Panama, the Gorgas Institute, the Children's Hospital, the Institute of Scientific Research and Advanced Technology Services, the Technological University of Panama, the Ministry of Health, and the University of Chiriquí. Keyword terms show a concentration on tropical forest trees, diversity and variation, considering mostly the effects of particular physical and biological causes. Output has grown steadily for several decades and continues to grow. The SCI-EXPANDED citations remain relatively stable and the lifespan of articles exceeds 20 years, with top citation four years after publication. The Impact Factor as currently measured is not appropriate to know the impact of Panamanian research. Our results only apply to the literature in the SCI-EXPANDED. Panama has nearly 100 scientific journals that are not taken into account by the SCI-EXPANDED. Thus the full productivity of authors and institutions, and their impact, remain to be studied, but our data represent a valid baseline for future research. Rev. Biol. Trop. 63 (4): 1255-1266. Epub 2015 December 01.

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Honduras is the second largest country in Central America, but 63 % of its population lives in poverty and it is the Central American country with less scientific journals. Even though Honduras has been included in general studies about Latin American science, there are no specific bibliometric studies about the productivity of the country, so this is the first formal study about the most productive institutions, fields and authors in Honduras. The Science Citation Index Expanded (SCI-EXPANDED), Web of Science Core Collection was used to collect the bibliographic data. There are no Honduras publications from 1903 to 1972 in SCI-EXPANDED. Honduras publications from 1973 to 2015 were further analyzed. A total of 1 146 Honduras publications with 13 document types in the Science Citation Index Expanded from 1973 to 2015 were found. Nearly 95 % of the articles in the database are in English, suggesting that articles in this language have the greatest visibility in the database, similar to other Central American countries. The countries with which Honduras publishes (e.g. Mexico, other Central American countries) follow the geographic and cultural affinity model, i.e. researchers tend to collaborate with colleagues that have similar culture or that are geographically close. This pattern has been found for other Central American countries. The focus of Honduran scientists in health and agriculture problems is typical on the less developed countries; on this respect Honduras is more similar to its closest neighbor, Nicaragua, than to smaller but more developed Central American countries like Panama and Costa Rica. Overall, the situation of scientific research and output in Honduras is improving, with more articles and citation in the SCIEXPANDED, and this positive trend should bring about benefits for the people of Honduras.