The Maltese letter 'għ' in taxonomy

The 9th letter of the Maltese alphabet is a digraph written as għ and pronounced 'għajn' (aighn in English). In speech, it is a silent consonant which has the function of lengthening the succeeding vowel, therefore a word written as 'għar' (meaning 'cave') would be pronounced something like 'aar'.

Several placenames in the Maltese Islands bear the letter għ - Għarb, Bengħisa and Għargħur being a few examples. Taxonomists naming animals from such places for their type locality have to use gh instead of għ in the specific epithet, simply because the ICZN does not allow for any characters other than the 26 of the Latin alphabet (Article 11.2).

Through the literature cited, I was able to come across five such animals described from the Maltese Islands. Clio ghawdexensis Janssen, 2003 is a fossil pteropod named after the island of Gozo, known in Maltese as Għawdex. Trochoidea gharlapsi Beckmann, 1987 is another snail, this time a recent terrestrial species localized mainly around the area of Għar Lapsi ('Lapsi Cave') in southern Malta (juvenile specimen illustrated below, photographed in December 2009).

However, both the above-mentioned type localities are (nomenclaturally) one-offs. The place to boast most species named for it is Għar Dalam (Dalam Cave), which is an extremely important location for fossils of the dwarf elephants and hippopotami that roamed Malta during the Pleistocene. Armadillidium ghardalamensis Caruso & Hili, 1991 is a woodlouse that is endemic to this cave and another one close by (Għar Ħassan). Scolopax ghardalamensis Fischer & Stephan, 1974 is a fossil bird described from the place, though this is now known to be a junior synonym of Coturnix coturnix (Linn., 1758). Finally, Myotis ghardalamensis Storch, 1974, an early Pleistocene bat, probably ancestral to the more modern species.

The million-dollar question is, how would these names, purely hypothetically or actually, be pronounced? Would the Maltese letter għ retain or lose its linguistic characteristics when included in a species' Latinized name? If binomial names were commonly used, would one speak of Trochoidea 'garlapsi' [sic], or Trochoidea 'aarlapsi' [sic]?

References:

Beckmann, K. -H. (1987). Land und Süßwassermollusken der Maltesischen Inseln. Heldia, 1 (Sonderheft): 1-38.
Caruso, D. & Hili, C. (1991). Nuovi dati sugli isopodi terrestri delle isole dell’arcipelago maltese. Animalia, 18: 115-124 .
Fischer, K. von & Stephan, B. (1974). Eine pleistozäne Avifauna aus der Ghar Dalam-Höhle, Malta. Zeitschrift für Geologische Wissenschaften, 2 (4): 515-523.
Janssen, A. W. (2004), Fossils from the Lower Globigerina Limestone Formation at Wardija, Gozo (Miocene, Aquitanian), with a description of some new pteropod species (Mollusca, Gastropoda). The Central Mediterranean Naturalist, 4 (1): 1-33.
Olsson, S. L. (1976). Fossil woodcocks: an extinct species from Puerto Rico and an invalid species from Malta (Aves: Scolopacidae: Scolopax). Proceedings of the Biological Society of Washington, 89 (20): 265-274.
Storch, G. (1974): Quartäre Fledermaus-Faunen von der Insel Malta. Senckenbergiana Lethaea, 55: 407-434.

Note: I edited my own comment below to articulate a sentence better, the original comment has been deleted and replaced with the slightly amended one.

Melarhaphe neritoides - before and after

Melarhaphe neritoides (Linn., 1758) is a seasnail which spends the summer months aestivating in cracks on bare rock, in a part of the shore where the sea does not reach, sealing up its aperture with a solid horny operculum to prevent losing water in the extreme heat accumulating during the day.

As soon as winter comes, more powerful waves and heavier mist start wetting the area where the snail lives, eventually filling pools in the rock and allowing the snail to resume its 'normal' lifestyle - moving about, grazing on algae, mating and laying eggs, in time before the dryness returns.

The following photographs were taken in the same rock hollow in August (photo 1) and December (photo 2) on the limestone shore of Buġibba, Malta, showing the snail during its period of inactivity and its subsequent 'resurrection'.

Research Paper 2

Cilia, D. P. (2009). On the presence of the alien freshwater gastropod Ferrissia fragilis (Tryon, 1863) (Gastropoda: Planorbidae) in the Maltese Islands (Central Mediterranean). Bollettino Malacologico, 45: 123-127.

Downloadable here: http://www.box.net/shared/qpfhcslgpf

Research Paper 1

Mifsud, C. & Cilia, D. P. (2009). On the presence of a colony of Brachidontes pharaonis (P. Fischer, 1870) (Bivalvia: Mytilidae) in Maltese waters (Central Mediterranean). Triton, 20: 20-21.

Downloadable here: http://www.box.net/shared/qj8q729mcn

Part III: The Biogeography of the Maltese Islands

The species found in the Maltese Islands give a clear picture of the origin and previous connections to the surrounding lands.

The shelled slug Testacella riedeli is the only terrestrial gastropod showing strong affinities with North African fauna (Giusti et al., 1995), however, this group of fauna is also derived from South European forms, which survived on landmasses fragmenting from South Europe and colliding into North Africa in the Early Miocene. The majority of animals and plants are closely related to Sicilian organisms, with fossils excluding the possibility that these were imported through human agency.

As an archipelago, Malta probably started to become exposed during the Messinian Salinity Crisis in the late Miocene. The virtual absence of macrofossils in some areas of the UCL suggests a supralittoral (or intertidal) landmass (Pedley et al., 1976). Subsequently, the archipelago was probably submerged and exposed several times with fluctuating sea levels and tectonic activity up to the Pleistocene. Pliocene deposits are absent on the Maltese Islands, suggesting aerial erosion.

The earliest suggestions for links with Sicily can be seen in the Quaternary deposits of Ghar Dalam, which contain fauna similar to that in mainland Europe such as species of Ursus, Palaeoloxodon, Cervus, Hippopotamus and other large mammals. Subsequent isolation of Malta can be deduced by the progressive dwarfing of some of these mammals in a process known as insular dwarfism (Zammit-Maempel, 1989) and the reverse process (insular gigantism) in the lizard Lacerta siculimelitensis (Boehme & Zammit-Maempel, 1982).

More information on the origin of the Maltese Islands is evident by looking at the clausiliid snails (Thake, 1985). Lampedusa originated from a Sicilian ancestor and invaded the land presently containing Malta and Lampedusa island in the Late Miocene. This is supprted by the fact that the island of Lampedusa harbours a species similar to the Maltese Lampedusa, namely L. lopadusae. On isolation of the islands during the Pliocene, the Lampedusa sp. in Malta differentiated into L. imitatrix which later also gave rise to L. melitensis.

Subsequently, either the sea-level fell again or the landmass rose so that Malta became connected to Sicily again. The Lampedusa-like ancestor on Sicily had meanwhile evolved into Muticaria macrostoma, which took the opportunity to invade the islands again. Being more competitive than Lampedusa sp., it managed to take over the areas occupied by Lampedusa, which it pushed to a restricted area on the southern coast of Malta. Interestingly, the island of Filfla was probably already detached from the Maltese mainland since Muticaria does not occur there, but a form of L. imitatrix thrives. Muticaria evolved into local forms following subsequent isolation of the Maltese mainland.

Plants are also mostly allied with South Europe forms, for example, Iris sicula and Ophrys oxyrrhyncos are endemic to Malta and Sicily. A relatively weaker North African link is also shown in plants such as Crucianella rupestris and Hypericum aegypticum.

References:

Boehme, W. & Zammit Maempel, G. (1982) Lacerta siculimelitensis sp. n. (Sauria: Lacertidae), a giant lizard from the Late Pleistocene of Malta. Amphibia-Reptilia, 3 (2-3), pp. 257-268.
Giusti, F., Manganelli, G. & Schembri, P. J. (1995). The non-marine molluscs of the Maltese Islands. pp. 1-608, Torino.
Pedley, H. M., House, M. R., & Waugh, B. (1976), The Geology of Malta and Gozo. Proceedings of the Geologists’ Association, 87, pp. 325-341.
Thake, M. A. (1985). The biogeography of the Maltese Islands, illustrated by the Clausiliidae. Journal of Biogeography, 12, pp. 269-287.
Zammit Maempel, G. (1977). An Outline of Maltese Geology. pp. 1-44, Progress Press, Malta.
Zammit Maempel, G. (1989). Ghar Dalam – Cave and Deposits. pp. 1-74, PEG, Malta.

Part II: The endemic species of the Maltese Islands

The Maltese Islands, though small, boast a considerable number of endemic species and infraspecific forms, consisting of 23 plants and 55 animals (Schembri, 1994).

Such species, apart from being unique, are biologically important because they show reproductive isolation and speciation at work. The lizard Podarcis filfolensis is perhaps the best known example of this, having evolved into different sub-species on most of the islands of the archipelago. It is the only endemic vertebrate in addition to the shrew Crocidura sicula calypso.

Terrestrial molluscs are a type of animal that evolves relatively quickly, in fact, 14% of the endemic animals are gastropods. Of these, the most interesting are the Hygromiidae and the Clausiliidae, which give clues as regards the isolation of the Maltese Archipelago from the surrounding land. The endemic snails Cernuella caruanae and Trochoidea spratti are relatively widespread, but the rarest gastropod is also an endemic – Lampedusa melitensis is a clausiliid whose population only consists of a few hundred individuals in a restricted ‘rdum’ area at Dingli. A sister species is Lampedusa imitatrix which is found further to the west along the southern coast of Malta. The last endemic clausiliid is Muticaria macrostoma, a taxon previously thought to consist of four different species, but these are anatomically indistinguishable (Giusti et al., 1995). The forms mamotica and scalaris are extremely restricted and therefore vulnerable. The forms macrostoma and oscitans, on the other hand, are frequent and one form prevails according to the geographical location. The southern coast of Malta (including Dingli) harbours the oscitans form.

81% of the endemic animal species are arthropods. These include the beautiful Maltese race of the butterfly Papilio machaon as well as the well-known freshwater crab Potamon fluviatile.
Endemic plants of the Maltese Islands are usually relicts from larger populations in a time when Malta was joined to Europe by a land bridge, for this reason they are called palaeoendemics. These are mostly restricted to rupestral habitats where they have competitively excluded other plants by tolerating harsh conditions such as high salinity. At Dingli, one can witness the species Darniella melitensis, Jasonia bocconei, and Palaeocyanus crassifolius, which is also Malta’s national plant. Cremnophyton lanfrancoi and Allium lojaconoi, a wild garlic that forms part of a cluster of similar species in central Mediterranean islands, are other palaeoendemics. Other endemic plants with more recent evolution are the orchid Anacamptis urvilleana and two species of Limonium, for this reason, they are referred to as neoendemics.

Figures:

Fig. 4. Muticaria macrostoma form macrostoma, from Floriana, Malta

Fig. 5. Muticaria macrostoma form oscitans, from Siġġiewi, Malta

References:

Giusti, F., Manganelli, G. & Schembri, P. J. (1995). The non-marine molluscs of the Maltese Islands. pp. 1-608, Torino.

Schembri, P. J. (1994). Natural heritage. In: Frendo, H. & Friggieri, O. (eds) Malta – Culture and Identity. pp. 105-124; Ministry of Youth and the Arts, Valletta, Malta

Introduction Part 1: The stratigraphy of the Maltese Islands

The exposed sedimentary rocks of the Maltese Islands date back from the late Oligocene, in the Chattian period, to the late Miocene, in the Messinian period. Strata as old as the Cretaceous are present beneath the oldest exposed layers, evidence for these was obtained through examination of fossilized spores (Pedley et al., 1976).

The first Oligocene stratum exposed in Malta is the Lower Coralline Limestone (LCL). This rock is composed mainly of rhodophytes with occasional coral horizons. The predominant rhodophyte genera are Lithothamnion and Archaeolithothamnion, both of which still exist. Since these require light for autotrophic processes, the environment was probably largely shallow water with calm conditions. In some areas where this layer is exposed, gigantic foraminifers such as Heterostegina and Lepidocyclina are preserved. The top of the stratum consists of the so-called Scutella bed (Spratt, 1843), which is composed of tests of the burrowing echinoid Scutella subrotunda. A phosphorite layer (C0) is also present in some areas (Gatt, 2005).

The stratum immediately above the LCL may date from the late Oligocene (Janssen, 2004). This layer is the Lower Globigerina Limestone (LGL), which marks a deepening of the sea-level since it is composed of mainly of planktonic foraminifera, which require a deep water column for such large populations to arise. Other deep-sea species such as the endemic echinoid Coelopleurus melitensis also occur (Zammit-Maempel, 1969).The LGL is succeeded by the similar but paler Middle Globigerina Limestone (MGL), which does not contain many fossils where exposed. Finally, the Upper Globigerina Limestone (UGL) caps the deep-sea limestone unit. The C1 phosphorite layer divides the LGL and MGL while the C2 phosphorite layer divides the MGL and the UGL. Phosphorite horizons represent a slowing-down in the deposition rate of sediments and a welling of nutrients from deeper areas of the Mediterranean. Several fossils, mostly of holoplanktonic molluscs and echinoderms, as well as teeth of Chondrichthyes, are frequent.

The Blue Clay Formation (BCF) succeeds the UGL. This still shows a deep-sea deposition environment, but instead of carbonate particles, there is a shift towards clayey minerals probably derived from volcanic detritus in a nearby area, creating a muddy area. The BCF contains limonite (iron compound) nodules, and fossils found in this layer are frequently composed of the same mineral.

The Greensand Formation (GF) lies directly above the BCF. This thin layer is almost entirely absent in Malta, though quite frequent in Gozo, especially in the Gelmus area where it reaches a thickness of about 11m (Pedley et al., 1976). It is lithologically a soft sandstone containing high proportions of the mineral glauconite (a complex silicate). The foraminifer Heterostegina appears again, but as another species several times smaller than that found in the LCL. Echinoids, mostly Clypeaster spp., are extremely common, if not always intact. Some authors regard the GF as part of the Upper Coralline Limestone (UCL). This marks a return to shallow water conditions and is composed of organisms similar to those in the LCL, though this time the species Mesophyllum commune is the most important and abundant coralline alga (Bosence, 1983). Some brachiopods and molluscs with algal habitats can also be found together with relatively shallow-water species such as the bivalve Lima lima. Fossilized wave impressions in some areas of the UCL exposure shows that currents were extremely strong, confirming the shallow water hypothesis.

Further sedimentary rocks of Quaternary origin, formed after the Maltese Islands had emerged from the water, are also present at some areas. The Maghlaq coast is the location of an alluvial fan formed by the delta of a large river, while Fiddien Valley in Rabat has a considerable area of lacustrine (lake-formed) tufa with pulmonate gastropod fossils (Pedley, 1980) and imprints of tracheophytes such as Laurus nobilis (Zammit-Maempel, 1977). However, the most important Quaternary deposit is that at Ghar Dalam, which shows the successive remains from the early Pleistocene fauna to the arrival of Neolithic Man in Malta (Zammit-Maempel, 1989).

Figures:

Fig. 1. Heterostegina cf. depressa from the Lower Coralline Limestone, Xghajra, Zabbar, Malta

Fig. 2. Globigerinoides ruber from the Upper Globigerina Limestone at San Lawrenz, Gozo, Malta

Fig. 3. Heterostegina costata from the Greensand Formation at Gelmus Hill, Gozo, Malta

References:

Boehme, W. & Zammit Maempel, G. (1982), Lacerta siculimelitensis sp. n. (Sauria: Lacertidae), a giant lizard from the Late Pleistocene of Malta. Amphibia-Reptilia, 3 (2-3), pp. 257-268.
Bosence, D. W. J. (1983), Coralline algae from the Miocene of Malta. Palaeontology, 26, pp. 147-173.
Gatt, P.A. (2005), Syntectonic deposition of an Oligo-Miocene phosphorite conglomerate bed in Malta. The Central Mediterranean Naturalist, 4 (2), pp. 109-119.
Janssen, A. W. (2004), Fossils from the Lower Globigerina Limestone Formation at Wardija, Gozo (Miocene, Aquitanian), with a description of some new pteropod species (Mollusca, Gastropoda). The Central Mediterranean Naturalist, 4 (1), pp. 1-33, 4 pl.
Pedley, H. M. (1980), The occurrence and sedimentology of a Pleistocene travertine in the Fiddien valley, Malta. Proceedings of the Geologists’ Association, 91, pp. 195-202.
Pedley, H. M., House, M. R., & Waugh, B. (1976), The Geology of Malta and Gozo. Proceedings of the Geologists’ Association, 87, pp. 325-341.
Spratt, T. A. B. (1843), On the Geology of the Maltese Islands. Proceedings of the Geological Society, 4 (2:97) pp. 225-230.
Zammit Maempel, G. (1969), A New Species of Coelopleurus (Echinoidea) from the Miocene of Malta. Palaeontology, 12 (1), pp. 42-47, 6 pl.
Zammit Maempel, G. (1977), An Outline of Maltese Geology. pp. 1-44, Progress Press, Malta.
Zammit Maempel, G. (1989), Ghar Dalam – Cave and Deposits. pp. 1-74, PEG, Malta.