Large numbers of the leptomedusa Earleria bruuni were observed inside a semi-closed deep-sea caldera during a comparative survey of the macrozooplankton fauna inside and outside the Kurose Hole, Izu-Ogasawara Islands, by the remotely operated vehicle (ROV) ‘Dolphin-3K’, on 24 September 2000. The Kurose Hole is an inactive volcanic caldera of 790 m bottom depth, located within the Izu-Bonin island arc, south of Tokyo. Archived video and audio data from a dive by the human-occupied vehicle (HOV) ‘Shinkai 2000’, carried out 3 weeks after the ROV dives, was also analysed. During all dives within the caldera, E. bruuni was present in large numbers and, during the HOV dive, two specimens for morphological analysis were obtained. Herein, we report E. bruuni from the Pacific Ocean for the first time. The vertical profiles of environmental factors and the vertical distributions of gelatinous macrozooplankton taxa such as salps, ctenophores, hydromedusae, siphonophores and scyphomedusae, were extremely different inside and outside the caldera. Inside the caldera the water temperatures were warm and dissolved oxygen levels were high compared with outside. For each taxon, their distributions were characterized and compared between the inside and outside of the caldera, and with previous literature reports.

A freshly dead individual of the giant squid Architeuthis dux, presumably mutilated by a predator of bigger or comparable size, is reported from the south-western Indian Ocean in proximity to Reunion Island. The species was identified from body and beak morphology and validated genetically. The dorsal mantle length (DML) estimated from beak measurements (lower rostral length, LRL) varied between 2153 and 3060 mm depending on the allometric equation used. The Architeuthis dux individual described here is the biggest giant squid ever reported for the region.

Two female snapper-choking isopods Cymothoa excisa (body length 11 and 14 mm) were in the buccal cavity of two invasive lionfish Pterois volitans (total length 294 and 301 mm) collected in Alacranes Reef, southern Gulf of Mexico. This is the first record of C. excisa parasitizing invasive lionfish P. volitans in coral reefs of the Western Atlantic, where these isopods appear to have infected the host through adult prey-predator transfer.

Baited trap or pot fisheries are considered to have relatively few wider ecosystem effects on the marine environment, particularly when compared with towed mobile fishing gear. However, this assumption is rarely tested in the field. This study aimed to determine the composition of non-target species that occur in crustacean pots and to assess spatial and temporal differences in catches in the waters around the Isle of Man, Irish Sea. The data were collected using fishery independent surveys and a questionnaire study. Based on fishery independent surveys, a total of five taxonomic groups and 43 species occurred as by-catch. The dominant by-catch species was velvet crab Necora puber. The by-catch per unit effort (BPUE) for all of the non-target species was low particularly in comparison to towed bottom gear fisheries around the Isle of Man. BPUE of species composition varied considerably between different locations around the Isle of Man. The results of both the fishery independent and questionnaire data suggested that the by-catch rates varied with season with peak BPUE occurring in spring which then declined into autumn and winter. By-catch composition did not decrease significantly with an increasing target species catch. Overall, by-catch was low relative to target species catch which may be partially attributable to the use of escape panels in pot fisheries in the Isle of Man.

To examine the risk of transgenerational transfer of organotin compounds (OTs) in fish, tributyltin (TBT) and triphenyltin (TPT) compounds and their breakdown products were determined in both parental females and offspring of viviparous surfperch Ditrema temmincki collected from Japanese coastal waters. TBT concentrations (Mean ± SD) in the offspring (34 ± 5.7 ng Sn g−1 wet wt) were significantly higher (10–17 times) than in the parental females (2.8 ± 1.0 ng Sn g−1 wet wt). In the offspring, TBT was the predominant butyltin compound (82 ± 1.6% ∑BTs = TBT + DBT + MBT), and represented a greater proportion than in the parental females (51 ± 9.3% as TBT). TPT concentrations were significantly lower than TBT, and the ratio of TPT in parental females, relative to offspring, was different from TBT. TPT concentrations in the offspring (0.8 ± 0.3 ng Sn g−1 wet wt) were almost identical to those in the parental females (1.0 ± 0.5 ng Sn g−1 wet wt). TPT was the predominant phenyltin (∑PTs = TPT + DPT + MPT) in both offspring (73 ± 12% as TPT) and parental females (72 ± 18% as TPT). Results suggest that the transfer rate of TBT from parent to offspring could be much faster than its degradation rate in the offspring, accounting for higher accumulation of TBT in the latter. In contrast, the transfer rate of TPT is slower than its biodegradation, leading to a lower concentration of TPT in the offspring. It is therefore likely that the offspring might be at a higher risk from TBT than the parental females during their early growth stage in ovary in the viviparous surfperch whereas exposure to TPT is comparable in both generations.

In this research, we compared the anatomy and biomechanics of two species of mudskipper vs an aquatic sandgoby in view of terrestrial locomotion. Of particular interest was the relationship (if any) of pectoral fin movement with pelvic fin movement. We show that the pelvic fins of the terrestrial mudskippers studied herein, are retractable and move antagonistically with the pectoral fins. The pelvic fin of the sandgoby studied here is contrarily non-retractable and drags on any underlying substrate that the sandgoby tries to crawl across. We find that the pelvic and pectoral fin muscles of all fish are separated, but that the pectoral fins of the mudskipper species have bulkier radial muscles than the sandgoby. By coupling a detailed morphological investigation of pectoral-pelvic fins musculature with finite element simulations, we find that unlike sandgobies, the mudskipper species are able to mechanically push the pelvic fins downward as pectoral fins retract. This allows for an instant movement of pelvic fins during the pectoral fin backward stroke and as such the pelvic fins stabilize mudskippers through Stefan attachment of their pelvic fins. This mechanism seems to be efficient and energy saving and we hypothesize that the piston-like action might benefit pelvic–pectoral fin antagonism by facilitating a mechanical down-thrust. Our research on the biomechanics of tree-climbing fish provides ideas and greater potential for the development of energetically more efficient systems of ambulation in biomimetic robots.

The parasitic fauna of the small-spotted catshark, Scyliorhinus canicula in the north-eastern Aegean Sea was investigated. Twenty-one out of the 52 (prevalence 40.4%) specimens collected were found infected with parasites; an arthropod and two nematode genera. Seven specimens (prevalence 13.5%) were infected by a Neoalbionella sp. copepod. Ten and 14 specimens were infected by the nematodes Proleptus obtusus (prevalence 19.2%) and Anisakis sp. (prevalence 26.9%), respectively. Female S. canicula specimens were significantly more heavily infected during autumn and when the whole sampling period is considered. Nematode infection was significantly related to season, becoming progressively heavier from spring to autumn. No correlation was found between TL of specimens and number of parasites for males or females, irrespective of gender. The present study provided a first record of Neoalbionella sp., P. obtusus and Anisakis sp. infections of S. canicula in the north-eastern Mediterranean. The lower prevalence of Proleptus obtusus and the higher prevalence of Anisakis sp. infection recorded in this study may be due to prey availability and parasite populations in this locality.

Nesting of hawksbill turtles (Eretmochelys imbricata) was monitored in 2013 and 2014 at 20 nesting beaches along the shores of Melaka, Peninsular Malaysia. Total nest numbers found were 481 and 463 in 2013 and 2014, respectively. The mean clutch size in 2013 of 123.5 ± 32.3 (SD) was similar to that in 2014 (118.5 ± 39.7). The distributions of nests were not uniform among the 20 beaches, and a large number of nests were found in Padang Kemunting, Kem Terendak, and Pulau Upeh, where the beaches were not always long. The nest sites indicated that the hawksbill turtle preferred to build its nest within the woody vegetation zone. The preferred vegetation species was Scaevola taccada. The temporal nesting pattern was year-round in both years, but the peak nesting season was between May and August, in the south-west monsoon season, possibly due to the gentle winds during this period. The turtles tended to nest between 22:01 and 24:00 h. This study provides basic information about hawksbill turtle nesting and insights into their spatial and temporal nesting preferences, which will contribute towards the conservation of this endangered species.

Evaluating the occurrence of diseases in aquatic mustelids is a priority in the conservation strategies for the Neotropical river otter and giant otter. Thus, the objective of this study was to determine the frequency of infection caused by Cryptosporidium spp. and Giardia sp. in both host species in northern Brazil. The collection of biological samples was carried out in the states of Amapá, Amazonas, Pará and Rondônia, totalling 337 faecal samples of these species, which were processed using Kinyoun's technique for the identification of Cryptosporidium spp. oocysts, and centrifugal flotation in zinc sulphate solution for visualization of Giardia sp. cysts. All samples were also tested by direct immunofluorescence. The frequency of infection by Cryptosporidium spp. was higher than Giardia sp., in the two otter species. In the analysed samples co-infection by both protozoa was also found in 4.47% (14/313) of Neotropical river otter and 20.83% (5/24) of giant otter samples. Oocysts and cysts of Cryptosporidium and Giardia, respectively, may remain infectious within specific environmental conditions for long periods of time. The current identification of Neotropical and giant otters as hosts of these protozoa increases the possibility of infection in this species and the transmission of those agents to other aquatic and terrestrial organisms, as well as to human populations. The findings of this study represent the first description of Cryptosporidium spp. and Giardia sp. affecting Lontra longicaudis and Pteronura brasiliensis.