A synthesis of the echinoderm fauna of the Maltese Islands

A review of existing literature records of echinoderms from Malta and a study of a large collection of specimens was carried out between 2000 and 2004 so as to update and produce a validated checklist of echinoderms occurring in Maltese waters. Seventy different species of echinoderms are recorded, including a number of species for which only single records exist for the Maltese islands and five species that were not found in the present study. The Maltese echinoderm fauna includes 45% of the 153 recorded Mediterranean echinoderm species, and apart from two aliens, is typical of the central Mediterranean region.peer-reviewe

On the occurrence of Agama agama (L.) (Reptilia : Agamidae) in the Maltese Islands

A live female specimen of Agama agama (L.) was found amongst crates of imported beer at Marsa, Malta in October 1979. This lizard was probably transported to Malta from North Africa with cargo.peer-reviewe

Malta : food, agriculture, fisheries and the environment

The Maltese archipelago, occupying an area of c.316 km 2 and situated in the central Mediterranean, consists of the inhabited islands of Malta and Gozo and a number of uninhabited islets and rocks. The islands are composed mainly of limestone of Oligo-Miocene age. Soils are young, show little horizon development, and are very similar to the parent rocks. There are no mountains, streams or lakes, but only minor springs. The main geomorphological features are karstic limestone plateaux, hillsides covered with clay taluses, and gently rolling limestone plains. The southwest coast is mainly steep sea-cliffs and the land tilts gently seawards to the northeast. The islands are riven by valleys which drain runoff during the wet season. The average annual rainfall is c . 530 mm of which some 85% falls during the period October to March. The mean monthly temperature range is 12-26°C. The islands are very windy and sunny. Natural water resources depend on percolating rainwater which collects in limestone aquifers. The flora and fauna are rich with c. 2,000 species of plants and more than 3,000 species of animals recorded to date; a relatively large number of species are endemic. The main ecosystems are maquis, garrigue and steppe. Minor ones include patches of woodland, coastal wetlands, sand dunes, freshwater and rupestral communities and those of caves. Human impact is significant. The resident population density is 1,140 per km2. Some 38% of the land area is cultivated and c.16% is built up. Environmental problems include accelerated soil erosion, quarrying, disposal of waste, high levels of chlorides and nitrates in the water supply, and loss of habitats and wildlife. The most important environmental issue at present is the rational use of land, a problem which is only now being tackled by the Maltese Government.peer-reviewe

Feeding behaviour of fifteen species of hermit crabs (Crustacea : Decapoda : Anomura) from the Otago region, southeastern New Zealand

Hermit crabs are common and conspicuous; members of intertidal and subtidal habitats. Although there exists an extensive literature on their behaviour, in the main this deals with :shell related behaviour :such as shell selection and shell fighting, and with behaviour patterns associated with the various symbiotic relationships of which hermit crabs form part (see the extensive bibliography in the recent review of hermit crab behavioural ecoloKv by Hazlett 1981). Other aspects of their behaviour have received much less attention . A number of studies on hermit. crab tee(ling behaviour have been made. However, relative to the number of living species (estimated at '" 700, Alcock 1905, Gordan 1956) very few have been investigated. Moreover, those species which have been studied to date all belong to genera of only two out of six families of marine hermit crabs (the Diogenidae and the Paguridae), and are intertidal or shallow water species. The feeding behadour of hermit crabs belonging to less well known families or genera or from less accessible habitats has not been studied. Nonetheless the available'data are sufficient to show that these animals have a wide range of feeding mechanisms including deposit-feeding, suspension-feeding, predation and scavenging. Often a species is able to feed in different ways depending on what food is available at the time (Kunze and Anderwn 1979, Schembri, 1982). Given such complexity of behaviour: (1 larger cross-section of species from a wider taxonomic range and from more diverse habitats needs to be investigated before evolutionary trends and adaptive radiation within the group can be studied. Sixteen species of hermit crabs belonging to four families are known to occur in the Otago region (table I; the late E. J. Batham unpublished data, C. L. ;McLay), personal communication) in habitats ranging from rocky intertidal through relatively coarse sediments of various sorts on the continental shelf to finer sediment:; on the continental shelf edge and slope. This rich fauna presented an ideal opportunity to study feeding in hermit crabs from a variety of taxonomic grouping and habitat types. Here the feeding behaviour and feeding mechanisms of 15 species of Otago hermit crabs are described and discussed in relation to their morphology habitat and previous work on feeding in hermit crabs.peer-reviewe

Seasonal changes in populations of Caulerpa taxifolia var. distichophylla in the Maltese Islands

Caulerpa taxifolia var. distichophylla, an alien alga in the Mediterranean Sea, was first recorded from the Maltese Islands in 2013. Initial observations suggested that it underwent complete frond regression in winter, possibly due to the colder temperatures. Since then it has spread rapidly and has become abundant in the infralittoral in some localities. The present two-year study on the Maltese populations indicates that the alga is able to resist low seawater temperatures during the winter and is not regressing completely, potentially increasing its ecological impact.peer-reviewe

Locomotion, feeding, grooming and the behavioural responses to gravity, light and hydrostatic pressure in the stage I zoea larvae of Ebalia tuberosa (Crustacea : Decapoda : Leucosiidae)

The stage I zoeae ofEbalia tuberosa swam by sculling with the exopodites of the 1st and 2nd maxillipeds and flexed the abdomen to brake or change direction. The larvae gained depth by stopping all natatory movements and sinking passively at rates of ~6mms -1. The zoeae refused both living and dead nauplii of Artemia spp., as well as two species of diatoms, but fed readily on detritic material on the bottom which they scooped up using the endopodites of the maxillipeds and pressed against the mouthparts using the telson. The setae on the posterior border of the telson were used for grooming the maxillipeds and the anterior mouthparts. Day-old stage I zoeae were negatively geotactic, positively phototactic and responded to pressure increases by swimming upwards and by high barokinesis. By the third day some larvae had become positively geotactic but were photopositive, and the majority responded to pressure increases as in the dayold larvae. Five-day old larvae were still photopositive but the majority had become positively geotactic and fewer numbers responded to pressure. Seven-day old larvae failed to respond to any of the stimuli used and assumed a predominantly benthic lifestyle. It is suggested that this anomalous behaviour is related to the dispersal of the larvae and to the specialized habitat requirements of the adults while the rather unusual morphology of the larvae is related to their feeding behaviour and semi-benthic lifestyle.peer-reviewe

The complete contents of 'The Mediterranean Naturalist', a periodical published in Malta between 1891 and 1893

An account is given of the journal "The Mediterranean Naturalist', edited and published by John Henry Cooke (1862- 1933) towards the end of the nineteenth century. The complete contents of the twenty-seven issues in three volumes are listed, with an indication of those articles concerning Malta or with a Maltese connotation.peer-reviewe

Occurrence of the alien sea hare Aplysia dactylomela Rang, 1828 (Opisthobranchia, Aplysiidae) in Malta

The alien sea hare Aplysia dactylomela, which is already established in several localities in the central and eastern Mediterranean, is recorded for the first time from Malta on the basis of a specimen hotographed at Cirkewwa (northern Malta). It is hypothesised that the occurrence of this species in Malta is a recent event and may be due to range expansion of the species.peer-reviewe