The marine biodiversity of the south-east coast of India is rich and varied. This article deals with the availability of molluscs from the trash fish from the Cuddalore coast, Tamilnadu, south-east coast of India, viz., Mudasalodai (11°29′N 79°46′E) and Cuddalore (11°42′N 79°46′E) landing centres. A survey has been done to estimate the composition of molluscs from October 2007 to September 2008. About 250 trawlers from Cuddalore and 200 trawlers from Mudasalodai were engaged in fishing activity every day up to a depth of 30–80 m. A total of 59 species belonging to 35 genera from 25 families were recorded at Station 1 and 57 species belonging to 32 genera from 24 families were identified at Station 2. The most diverse families were Muricidae, Conidae, Arcidae and Veneridae at both stations. The Shannon diversity index of gastropods varied from 2.27 to 4.71 and bivalves varied from 1.82 to 2.52, the species richness of gastropods varied from 2.75 to 6.27 and bivalves varied from 1.42 to 1.75. The species evenness in the gastropods was between 0.58–0.90 and 0.57–0.74 in gastropods and bivalves respectively. Seasonal contribution of gastropods attained maximum in pre-monsoon and minimum during the summer at both stations. At Station 1 bivalves attained maximum in pre-monsoon and minimum was recorded during monsoon. Seasonal contribution of bivalves at Station 2 was high in post-monsoon and minimum in the summer.

Desmapsamma anchorata has been recorded overgrowing Tubastraea coccinea and Tubastraea tagusensis on two sites at Ilha Grande, Rio de Janeiro, Brazil. The records of D. anchorata overgrowing and killing T. coccinea and T. tagusensis showed that this native sponge could be an important competitor for the invasive corals.

Udotea argentea, a broadly distributed Indo-Pacific seaweed, has been collected for the first time on the south coast of Oahu, Hawaii. The habit and anatomical features are illustrated and the possible ecological impact to the native benthic community is discussed.

A small holothurian, Rhabdomolgus ruber, was found in a number of grab samples from subtidal sedimentary sites within the Lough Hyne Marine Nature Reserve, West Cork, Republic of Ireland. Previously this species has only been recorded in waters off Helgoland, Germany and in the plankton near Cherbourg, France. This result significantly extends the known geographical range of this species to Irish waters.

Three species of hard corals including Echinopora gemmaceaLeptoria irregularis (Faviidae) and Montipora incrassata (Acroporidae) were recorded for the first time from north-east of Larak Island in the Strait of Hurmoz, Persian Gulf in late 2008. The review of previous studies revealed that these species were new reports from Larak Island situated in the northern Persian Gulf. Of these species only Echinopora gemmacea has previously been reported from the Oman Sea. No evidence of Leptoria irregularis and Montipora incrassata has been reported from the southern Persian Gulf and Oman Sea.

In June 2009, a white rough-toothed dolphin (Steno bredanensis) calf was photographed in a group of at least 50 dolphins in the southern Gulf of Guinea, 95 nauticol miles off the Gabon coast (01°45′S 007°29′E), West Africa. Reports of unusually pigmented cetaceans are infrequent and this record represents the first of an all-white rough-toothed dolphin. Furthermore, there is little documentation concerning rough-toothed dolphins and this note contributes to the knowledge of this species in tropical West African waters.

The occurrence of Cetorhinus maximus in Chilean waters is reviewed based upon biological, geographical and temporal data obtained from 30 specimens observed between 1905 and 2009. These records were established from 27°40′S (Punta de Cachos, Bahía Salado) to 55°45′S (Cabo de Hornos). Both males and females were incidentally caught in artisanal gill-net fisheries. The records suggest a segregation of C. maximus by groups of sex–size. Temporal data suggests that C. maximus primarily occur in Chilean coastal waters during spring and summer.

This paper reports on the occurrence of the sei whale (Balaenoptera borealis) in the south-western Atlantic. Only in recent years have sei whale sightings been reported regularly within the surveyed area. In a total of 20 sightings, 65% were reported from August to September. Group size was small, averaging 1.94 (SD = 1.21) individuals per group. During this study, feeding behaviour and interactions with seabirds were observed and are here described. Comparison of our results with historical data from the whaling industry showed that whales were observed where expected based on past catches. Further studies are necessary in order to assess the status of sei whales in the south-western Atlantic. However, our data might indicate a slow recovery in the region. This information will be useful for the conservation of the species in this area and in the southern hemisphere.

Molidae are tropical marine teleosts that occur in all oceans. Among the species described, Masturus lanceolatus is considered rare on the Brazilian coast, with only four records found in scientific publications. The present study reports the first occurrence of this species for the coast of the State of Pernambuco (north-eastern Brazil) and discusses the possible causes of its being stranded. The specimen was found alive in the estuary of the Una River in the city of São José da Coroa Grande on the southern coast of the state. The fish was unknown to the local community of fishermen, who considered it a ‘bad omen’. The occurrence led to an environmental education project in the community carried out by members of the Tropical Marine Ichthyology Group, which carried out an inspection, documentation, analysis of external injuries and collection of viscera for the subsequent histological analysis. After undergoing taxidermy, the specimen was donated to the Una Museum. Analysis revealed that the fish suffered from an intense inflammatory process of the liver caused by polycystosis of nematodes and Trypanorhyncha, which resulted in malnutrition, as observed by the low body weight. Moreover, a likely stranding left the specimen more vulnerable to different species of shark, which mutilated it, hindering its locomotion. This fish appears to have drifted and was thrown against the reefs near the estuary before its stranding.

Distribution, reproductive biology and biochemical composition of Rhopalophthalmus indicus were investigated based on samples collected over a period of one year from Cochin backwater. Rhopalophthalmus indicus was recorded throughout the year with peak abundance during pre-monsoon. The population density was influenced by chlorophyll-a, dissolved oxygen, salinity and water temperature. The species showed periodicity in the abundance and produced more than one generation per year. The number of embryos carried by a single female ranged from six to 13, and was correlated with female body length (P > 0.05), tending to increase with the size of the female. Egg size varied between 0.42 and 0.47 mm, and was independent of female size. Both males and females attain sexual maturity at a length of 8.4 mm. Seasonality is observed in biochemical composition, as mature males and females had higher protein contents, immature stages contained high carbohydrate content and brooding females accumulated more lipids.

We used timed underwater visual censuses to study grouper relative abundance and diversity on the west coast of India. Eighteen grouper species were observed in these surveys, including two new records for the west coast of India, Aethaloperca rogaa and Plectropomus areolatus. Cephalopholis formosa and Epinephelus faveatus were the most abundant species observed with the latter more numerous on inshore than offshore rocky reefs. Ecological and distributional notes are given for the species observed.

The occurrence of a living population of the giant deep-sea oyster Neopycnodonte zibrowii is reported on the slopes of Hespérides Mud Volcano Complex in the Gulf of Cádiz, south-western Iberian Peninsula, in 720 m depth. A noteworthy circumstance of this new record is its situation on a sea bottom which was suitable for the operation of a rock dredge and does not apparently feature abrupt cliffs or rocky overhangs as in previous reports on the species.

Studland Bay contains an extensive seagrass (Zostera marina) bed and two species of seahorse: spiny (Hippocampus guttulatus) and short snouted (H. hippocampus). All are protected under UK and international legislation. Five H. guttulatus have been tagged and all re-sighted several times within the seagrass bed. Home ranges of 30–400m2 were found. The three tagged males have all been observed to be pregnant throughout the summer months suggesting up to five broods per year. On one occasion the courtship display was recorded. This study has demonstrated the value of volunteer divers in monitoring which would not have been so successful without them. This project arose from concerns over negative impacts of boat anchoring and mooring on the seagrass habitat. It is hoped that the insights gained into site fidelity, territory size and breeding ecology of the seahorses will contribute to management plans for this unique site.

The symbiotic alpheid shrimp Aretopsis amabilis De Man, 1910 (Decapoda: Caridea: Alpheidae) is reported from Vietnam for the first time. A male–female pair of mature individuals of this species was found inside a large strombid shell occupied by a hermit crab Dardanus cf. lagopodes (Forskål, 1775) (Diogenidae). The live coloration of the shrimps and their host, as well as its known associations and information on the species distribution are given.

The silver porgy (Diplodus argenteus) is an occasional cleaner of two species of fish in the southern portion of the south-west Atlantic. We record herein for the first time this fish species associating with green turtles (Chelonia mydas) and cleaning their carapaces. Only juveniles were recorded cleaning turtles, scraping off microorganisms that fouled the carapace.

The first finding of the alien crab Atergatis roseus (Xanthidae) in Rhodes Island (Hellenic south-eastern Aegean Sea) is documented, increasing to eleven the number of alien brachyurans present in the area, nine of them having Indo-Pacific origin. Due to its coloration, not in accordance with the literature, the specimen is described in detail.

The present paper provides the first record of the brachyuran crab species as by-catch from shrimp fishery practices in northern Rio de Janeiro State, south-eastern Brazil (21°30′S–21°50′S). Monthly samples were collected from April 2006 to March 2007 along the coastal fishing ground, from 0 to 4 nautical miles offshore and from 10 to 15 m depth. Eight species and 6833 crab specimens were recorded: Arenaeus cribarius (N = 11), Callinectes ornatus (N = 5613), Cronius rubber (N = 16), Hepatus pudibundus (N = 523), Libinia ferreirae (N = 202), Persephona mediterranea (N = 1), P. punctata (N = 466) and Portunus spinimanus (N = 1). A seasonal pattern of the crabs' occurrence was not found. The catches per unit effort values of C. ornatus were significantly greater than the other crabs and its high number indicates a resident pattern along the coastal fishing ground in the study area. The by-caught specimens of C. ornatus can be used as bait in Balistidae (triggerfish) fishery practice by the local fishermen, but the other crab species are discarded after by-catch.

Giant clams are endangered in many parts of their Indo-Pacific range owing to adult specific overharvesting that threatens recruitment, a demographic parameter exhibiting high sensitivity to environmental disturbances and adult densities among tridacnids. Lakshadweep reefs are not subjected to commercial giant clam fishery, and population assessment has not been carried out in these waters so far. We monitored the small giant clam Tridacna maxima populations in confined waters of 12 reefs in Lakshadweep Archipelago during 2005–2007 using a systematic line transect based distance sampling framework. Overall T. maxima density in the Archipelago was estimated at 141.2/ha (95% CL 118.2–168.7) in 2005 and 122.7/ha (103.60–145.37) in 2006. Populations showed wide variation in densities and relative proportions of different age-classes between reefs. While Agatti, Bitra and Chetlat lagoons harboured high clam densities, Amini harboured the most impoverished population. Data simulation showed that total clam count along transects of 100 m length × 2–5 m strip width, in a minimum of 140 replicates, stratified by area among lagoons, would provide a viable monitoring index for rapid assessments of T. maxima in Lakshadweep. Compared to unbiased absolute abundance estimates, this monitoring index could be achieved more easily, without much compromise on accuracy and precision, necessary for meaningful spatio-temporal comparisons.

New findings of the scleractinian coral Dendrophyllia laboreli in various localities off the European coast in the Gulf of Cadiz and the Strait of Gibraltar, as well as the Atlantic coast of Morocco, are reported. These new findings redefine the current northernmost known limit of distribution of this species, previously known in African localities from Ghana to the Canary Islands. Some ecological and biogeographical remarks are also included.

Some specimens of the blue crab are bearing barnacles which have been identified as Chelonibia patula. Although generally known in the Mediterranean Sea this is the first report of C. patula from the Turkish coasts. It has been photographed and some morphometric measurements are provided.