https://www.um.edu.mt/library/oar/handle/123456789/415 Fri, 04 Sep 2026 16:22:06 GMT 2026-09-04T16:22:06Z https://www.um.edu.mt/library/oar/handle/123456789/148898 Title: Nuclear following associations between Caranx crysos and two rays, Dasyatis pastinaca and Aetomylaeus bovinus, observed in Malta, Central Mediterranean Authors: Falzon, Mark-Anthony; Schembri, Patrick J. Abstract: An association of Blue runner, Caranx crysos (Carangidae), with two species of rays, Common stingray Dasyatis pastinaca (Dasyatidae) and Bull ray Aetomylaeus bovinus (Myliobatidae), in which an individual C. crysos (the follower fish) follows a foraging ray (the nuclear species), is described, based on a sample of 61 video clips. Follower fish show three types of behaviour: swimming under the pectoral fin of the nuclear ray, swimming above the mid-dorsal line of the nuclear ray and very close to it, or swimming above the ray and darting from side to side. The first two of these behaviours seem to be species-specific as the first is only shown when the nuclear ray is A. bovinus and the second when the nuclear ray is D. pastinaca. Following fish do not allow conspecifics to approach the nuclear ray but are mostly indifferent to non-conspecifics doing so. The following fish benefit from the association by feeding on prey disturbed by the foraging activities of the nuclear ray but the nuclear ray is unreactive to the following fish, suggesting that this is a case of trophic commensalism. Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/148898 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/148517 Title: The variability of Heteracris adspersa (Redtenbacher, 1889) re-examined (Orthoptera : Acrididae, Eyprepocnemidinae) Authors: Cassar, Louis F.; Lanfranco, Sandro; Massa, Bruno Abstract: A new subspecies of Heteracris adspersa was described in 1978 on the basis of morphometrics and structure configuration of the male subgenital plate from specimens collected in Sardinia. The present study examines specimens (n=175) from a broad suite of localities, ranging from the Middle East across to the western Mediterranean. Statistical analyses are subsequently carried out on a revised dataset comprising 94♂♂ and 55♀♀. Microscopic examination of the subgenital plate is also conducted on specimens from Sardinia, Sicily, Malta and Yemen and compared with those published in the original description. Findings demonstrate that the subspecies massai is practically an artefact of unintended consequence, essentially a case of taxonomic inflation, in view of evident intra and interpopulation variability across a wide geographic area; consequently, H. a. massai is synonymised. Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/148517 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/148513 Title: On the typification of Crepis pusilla (Asteraceae) Authors: Tavilla, Gianmarco; Lanfranco, Sandro Abstract: The name Melitella pusilla, basionym for the accepted Crepis pusilla, is lectotypified. The name was originally published within the monotypic new genus Melitella basing on plants collected by Sommier on Gozo Island (Maltese Archipelago). Specimens preserved at E, FI, GH, K, LY, MU, MW, VT, P, PI, SLA, VAL, WU, and Z herbaria have been examined. The lectotype is a specimen at FI. An earlier potential typification is dismissed, as the corresponding herbarium sheet bears plants collected on two different dates and is not therefore one specimen. Furthermore, M. pusilla var. laciniata, lacking any traceable original material, is neotypified with a specimen kept at VAL. Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/148513 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/148494 Title: Form meets function : role of macroalgal morphology in structuring mobile epifaunal assemblages in selected algae from the central Mediterranean Authors: Borg, Emma; Schembri, Patrick J.; Evans, Julian Abstract: Quantitative measurement of macroalgal thallus morphology and its link with epifaunal communities remains largely unexplored in the central Mediterranean. This paper explores the link between thallus morphology and the associated mobile epifaunal assemblages of three common macroalgae native to the Maltese Islands (central Mediterranean Sea): Ellisolandia elongata, Jania rubens, and Dictyota spp. (D. dichotoma, D. mediterranea, and D. fasciola in mixed assemblages). We hypothesised that macroalgal species exhibiting distinct morphological characteristics support mobile epifaunal assemblages that differ significantly in structure and composition. Using a full factorial framework, macroalgal beds dominated by each target species were sampled from shallow water in three localities on the northeastern coast of Malta, using SCUBA diving. Dry biomass and fractal dimensions were used to characterise the distinct morphological traits of the three macroalgal species. A total of 85 epifaunal taxa were associated with Dictyota spp., 98 taxa with E. elongata, and 112 taxa with J. rubens. Excluding the disproportionately abundant invasive foraminiferan Amphistegina lobifera, 911 individuals were recorded on E. elongata, 1224 on Dictyota spp., and 2233 on J. rubens. Of the 152 taxa identified across all macroalgae studied, Arthropoda (44 taxa) and Mollusca (39 taxa) dominated, with individuals occupying the small inter-frond spaces as shelters that provide refuge from predators and hydrodynamic stress. Multivariate analysis revealed that the structure and composition of mobile epifaunal assemblages were associated with the interaction between macroalgal morphology and site-specific environmental conditions. The more structurally complex, articulated, calcified, and densely branched forms of E. elongata and J. rubens supported more varied epifaunal communities that differed from those associated with the compressed and leafier thalli of Dictyota spp., which were instead dominated by surface-associated taxa. Notably higher richness and diversity values were recorded in sheltered sites, especially in the case of J. rubens, showing that the effect of habitat architecture may be modulated by wave exposure. Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/148494 2026-01-01T00:00:00Z