Bioinspired underwater legged robot for seabed exploration with low environmental disturbance.

Robots have the potential to assist and complement humans in the study and exploration of extreme and hostile environments. For example, valuable scientific data have been collected with the aid of propeller-driven autonomous and remotely operated vehicles in underwater operations. However, because of their nature as swimmers, such robots are limited when closer interaction with the environment is required. Here, we report a bioinspired underwater legged robot, called SILVER2, that implements locomotion modalities inspired by benthic animals (organisms that harness the interaction with the seabed to move; for example, octopi and crabs). Our robot can traverse irregular terrains, interact delicately with the environment, approach targets safely and precisely, and hold position passively and silently. The capabilities of our robot were validated through a series of field missions in real sea conditions in a depth range between 0.5 and 12 meters.

Exo-Ocean Exploration with Deep-Sea Sensor and Platform Technologies.

One of Saturn's largest moons, Enceladus, possesses a vast extraterrestrial ocean (i.e., exo-ocean) that is increasingly becoming the hotspot of future research initiatives dedicated to the exploration of putative life. Here, a new bio-exploration concept design for Enceladus' exo-ocean is proposed, focusing on the potential presence of organisms across a wide range of sizes (i.e., from uni- to multicellular and animal-like), according to state-of-the-art sensor and robotic platform technologies used in terrestrial deep-sea research. In particular, we focus on combined direct and indirect life-detection capabilities, based on optoacoustic imaging and passive acoustics, as well as molecular approaches. Such biologically oriented sampling can be accompanied by concomitant geochemical and oceanographic measurements to provide data relevant to exo-ocean exploration and understanding. Finally, we describe how this multidisciplinary monitoring approach is currently enabled in terrestrial oceans through cabled (fixed) observatories and their related mobile multiparametric platforms (i.e., Autonomous Underwater and Remotely Operated Vehicles, as well as crawlers, rovers, and biomimetic robots) and how their modified design can be used for exo-ocean exploration.

Insights into the genetic structure of the rabbitfish Chimaera monstrosa (Holocephali) across the Atlantic-Mediterranean transition zone.

A comparison of the genetic structure of Chimaera monstrosa populations from the Atlantic Ocean and the Mediterranean Sea was carried out using mitochondrial DNA analysis. Results indicate high and significant pairwise ΦST values with no shared haplotypes between the two areas. Furthermore, migration rate estimates suggested absence of gene flow between the two basins. These findings, coupled with the species vertical distribution, suggest that the shallow depth of the Strait of Gibraltar may act as a barrier limiting the dispersal capabilities of these populations, which likely became separated at the end of the middle Pleistocene.

Establishment of a coastal fish in the Azores: recent colonisation or sudden expansion of an ancient relict population?

The processes and timescales associated with ocean-wide changes in the distribution of marine species have intrigued biologists since Darwin's earliest insights into biogeography. The Azores, a mid-Atlantic volcanic archipelago located >1000 km off the European continental shelf, offers ideal opportunities to investigate phylogeographic colonisation scenarios. The benthopelagic sparid fish known as the common two-banded seabream (Diplodus vulgaris) is now relatively common along the coastline of the Azores archipelago, but was virtually absent before the 1990 s. We employed a multiple genetic marker approach to test whether the successful establishment of the Azorean population derives from a recent colonisation from western continental/island populations or from the demographic explosion of an ancient relict population. Results from nuclear and mtDNA sequences show that all Atlantic and Mediterranean populations belong to the same phylogroup, though microsatellite data indicate significant genetic divergence between the Azorean sample and all other locations, as well as among Macaronesian, western Iberian and Mediterranean regions. The results from Approximate Bayesian Computation indicate that D. vulgaris has likely inhabited the Azores for ∼ 40 (95% confidence interval (CI): 5.5-83.6) to 52 (95% CI: 6.32-89.0) generations, corresponding to roughly 80-150 years, suggesting near-contemporary colonisation, followed by a more recent demographic expansion that could have been facilitated by changing climate conditions. Moreover, the lack of previous records of this species over the past century, together with the absence of lineage separation and the presence of relatively few private alleles, do not exclude the possibility of an even more recent colonisation event.

Gaidropsarus (Gadidae, Teleostei) of the North Atlantic Ocean: a brief phylogenetic review.

The phylogenetic relationships among the North Atlantic Gaidropsarus and between the three Gaidropsarinae genera Gaidropsarus, Ciliata and Enchelyopus are reviewed with the hitherto most comprehensive taxonomic sampling of this group. Phylogenetic results (maximum parsimony, maximum likelihood and Bayesian inference) based on nuclear (rhodopsin) and concatenated mitochondrial (12s, 16s and cytb) markers clearly support this subfamily. For the north-eastern Atlantic species of Gaidropsarus, two previously unreported clades were strongly supported, clarifying the relationships within the genus, and revealing fewer distinct taxa in the north Atlantic Gaidropsarus than previously stipulated. The data challenge the specific status of Gaidropsarus mediterraneus and Gaidropsarus guttatus and raise doubts concerning the distinctiveness of other species. A taxonomic revision of the genus is suggested.

The eastern Pacific species of Bathygobius (Perciformes: Gobiidae).

The circumtropical gobiid genus Bathygobius Bleeker is defined and three Eastern Pacific species are redescribed, with first dorsal fin pattern and postorbital blotches being shown to be additional characters of diagnostic value. Two mainland species are recognised, the Mexican-Panamanian B. ramosus Ginsburg 1947 and the Panamanian B. andrei (Sauvage 1880). B. ramosus is now reported from Clarión Island, Revillagigedos, and also from Cocos Island. Meristic variation of ramosus is tabulated for local populations and PCA analysis of their morphometry suggests regional differentiation in this species, with Tres Marias and Revillagigedos populations clustering away from mainland and Montuosa material. An insular species, B. lineatus (Jenyns 1842) from the Galapagos is defined, with B. arundelii (Garman 1899) from Clipperton Island and B. l. lupinus Ginsburg 1947 from Lobos de Afuera, off Peru, placed as nominal subspecies of lineatus. This species resembles the Indo-west Pacific B. fuscus and Atlantic basin B. soporator more closely than it does ramosus and andrei and may be the product of transpacific dispersal. A similar origin for B. ramosus is discussed but it seems more likely that both B. ramosus and B. andrei have Caribbean sister species.

[Morphology and histochemistry of regenerating corneal epithelium in Triturus cristatus. 1. Preliminary observations]. / Morfologia ed istochimica dell'epitelio corneale rigenerante in Triturus cristatus. 1) Osservazioni preliminari

The corneal epithelium of Triturus cristatus was studied by light and electron microscopy. It consists of three cellular layers; the superficial cells, which show numerous short microvilli, are held together by typical junctional complexes. The basal cells adhere to the basal lamina by hemidesmosomes. Furthermore all cells form with the neighboring ones interdigitations and establish with them desmosomal contacts. Secretion granules and vesicles are present throughout the epithelium, mainly in the upper layer; they are filled with an electron dense material, containing glycoproteins as suggested by the histochemical analysis. Mitoses are very frequent in the basal layer. Occasionally exfoliating cells showing signs of degeneration were observed in the superficial layer. The morphological changes occurring during epithelization of wound linearly incised, were studied by light microscopy at several time intervals and the detachement and migration of the cells was particularly investigated. Very early after wounding (5') necrotic cells and cell debris are present at the wound edges. Soon after, thin protrusions originate from surrounding undamaged cells and push through the cellular fragments sliding on the underlining connective tissue. After 2 h, the wound is completely closed by such flattened protrusions. The newly formed epithelium becomes gradually thicker (3-7 h) and the mitotic activity till now suppressed, is resumed (24 h). Studies are in progress on the modifications of the junctional complexes and on the enzymatic mechanism possibly involved in cell mobilization.