Stephen Busack and Robin Lawson
Pairwise sequence polymorphism in mitochondrial DNA and levels of differentiation among presumptive gene loci (expressed as Nei's Dˆ) tend to be greater between populations separated by the Strait of Gibraltar than between populations inhabiting either Morocco or Spain. Ancestral Psammodromus algirus inhabiting Iberia and North Africa while the Strait of Gibraltar was being formed and stabilized (Miocene-Pliocene) evolved in association with physiogeographic change brought about by this barrier to gene exchange. Considered in units of genetic change per kilometer, mtDNA differentiation is greater in Morocco than in Spain, and allozyme differentiation is slightly greater than, or equal to, that in Spain, suggesting that P. algirus has a longer and more complex history in Morocco than in Spain.
Stephen D. Busack
Reported only from three general areas at elevations between 2500-3700 m within the High Atlas Mountains of Marrakech Prefecture, Morocco, Lacerta andreanszkyi appears little studied (Saint Girons, 1953; Pasteur and Bons, 1960; Bons, 1967; Klemmer, 1969). Since Werner's (1929) description of this apparently restricted apecies, nothing has been published regarding its biology. The following limited data concerning population density, biomass, sex ratio, feeding ecology, reproduction, frequency of injury, and thermal environment and response of this elusive species are presented below to partially fill this void.
Stephen D. Busack and Fabian M. Jaksic
Autecological aspects of Acanthodactylus erythrurus were examined at La Algaida, Cádiz Province, Spain. The male population is composed of 60 % adult and 40 % subadult individuals; male hatchlings increase in size at a rate of 0.06 mm/day from hatching ( 31 mm snout-vent length) to sexual maturity (∼61 mm); 50 % do not survive beyond 1.5 years, but those which reach adult size may live 1.9 years. Females grow from hatching (∼ 28 mm) to sexual maturity( 57 mm) at a rate of 0.05 mm/day; less than half survive 1.4 years and the life span of some individuals is 2.1 years. Adult males outnumber adult females 1.4:1, but subadult ratios are 1:1. Adults and subadults associate with different plant species during their activity period, but each age class tends to avoid open sand patches. These 8.4-13 g lizards feed on a wide variety of insects and appreciable quantities of plant material. 49% ofall males and 82% ofall females actively consume Halimium halimifolium. We suspect this lizard species is wide ranging and non-territorial ; only one agonistic encounter was recorded and it was interspecific (with Psammodromus algirus). The frequency of escape from predation is estimated at 26.8 %, based on tail-loss figures, and the incidence of cestode parasitism (Oochoristica cf. tuberculata) is 2.1 %. The population studied was highly resilient to 16 months of intense human predation.
Robin Lawson, Wendy Arjo and Stephen Busack
Mitochondrial DNA analysis indicates that Podarcis vaucheri is a species complex with one clade inhabiting both north and south shores of the Strait of Gibraltar and one clade restricted to North Africa. While each clade exhibits differing morphology, allozyme analysis suggests varying degrees of reproductive contact among populations within clades. Ancestral P. vaucheri appears to have been restricted to insular areas of the Betic-Rif Massif and mainland Africa during Miocene, with major lineage differentiation occurring during Pliocene.Our analysis further confirms that Podarcis atrata warrants species status and suggests that it may be more widely distributed than previously reported.
Jeanne A. Visnaw and Stephen D. Busack
Cádiz Province, Spain, is the southernmost extent of the range of L. lepida. Within this area, L. lepida demonstrates no distinct preference for any habitat and inhabits man-made and natural shelters with equal frequency. L. lepida is diurnal and active at the surface at ambient temperatures between 15.6°C and 42°C from February through November. Males are 4% to 8% heavier than females of equivalent body length. The rate of parasitism from nematodes is low (6%). The Cádiz Province population has the most diverse diet of any population studied to date. The taxonomic composition of the diet of males and females is identical, and consists mostly of invertebrate prey. Mean prey size and prey diversity are not correlated with lizard body size. Lacerta lepida is cannibalistic. Spermatogenesis and follicular development occur from April through July, egg laying occurs between early June and early July, and clutch size may vary from 4 to 18. Lacerta lepida reproduces only once annually.
Stephen D. Busack and Linda R. Maxson
Relationships among representatives of five genera of lacertid lizards from Iberia, Morocco, and South Africa were studied using quantitative micro-complement fixation analysis of serum albumin evolution. Using the albumin molecular clock to establish divergence times we suggest (1) South African Ichnotropis and North African Psammodromus diverged from the lineage representing Lacerta lepida-L. monticola during the Oligocene, (2) South African Pedioplanis and Heliobolus diverged from this lineage during the late Miocene, and (3) ancestral representatives of L. andreanszkyi, L. perspicillata and Podarcis hispanica diverged from lineages leading to L. monticola and L. lepida during the mid-Miocene. Radiation within the Palearctic Lacertidae has clearly been extensive, yet fewer than twenty percent of the species in this radiation have been examined biochemically. Until additional data can be gathered, the current classification of the Palearctic Lacertidae cannot be much improved and we recommend adherence to the taxonomy proposed by Arnold (1973).
Fabian M. Jaksić and Stephen D. Busack
Salvador Carranza, Alfredo Salvador, Joaquín Verdú-Ricoy, José Díaz and Stephen Busack
Relationships among Psammodromus algirus populations from the Iberian Peninsula and North Africa, including recently described P. jeanneae and P. manuelae, were estimated from mitochondrial DNA gene sequences. This enlarged data set confirmed the presence of two divergent eastern and western mitochondrial DNA lineages on the Iberian Peninsula, the distributions for which are separated by a narrow zone of contact across the centre of the Peninsula. Paratypes of P. jeanneae and topotypes of P. manuelae represent southern and northern clades of the western lineage, respectively, making P. algirus paraphyletic. This, together with the low level of allozymic and mitochondrial DNA substructuring within western populations, is not sufficient to retain P. jeanneae and P. manuelae as valid species, and we relegate them to the status of junior synonyms of P. algirus.