Parasites of juvenile golden grey mullet Liza aurata Risso, 1810 in Sarıkum Lagoon Lake at Sinop, Turkey

Juvenile golden grey mullet, Liza aurata were collected from Sar?kum Lagoon Lake which connected to the Black Sea at Sinop, Turkey and examined for parasitic fauna. A total of 219 fish were investigated throughout a 1-year period. Parasite species recovered were Trichodina lepsii, T. puytoraci, Gyrodactylus sp., Ligophorus cephali, Ligophorus mediterraneus, Solostamenides mugilis, Ascocotyle sp. (metacercaria) and Ergasilus lizae. Overall infection prevalence (%) and mean intensity values were 95.9% and 412.65 ± 85.31 parasites per infected fish, respectively. Infection prevalence and mean intensity values for each parasite species in relation to season and fish size were also determined and discussed. While Ligophorus cephali and L. mediterraneus are new records for Turkish parasite fauna, the juvenile Liza aurata is a new host record for Ligophorus cephali and L. mediterraneus.     

Lamium amplexicaule (Lamiaceae): a weed reservoir for tomato yellow leaf curl virus (TYLCV) in Korea

After the first identification of tomato yellow leaf curl virus (TYLCV) in the southern part of Korea in 2008, TYLCV has rapidly spread to tomato farms in most regions of Korea. From 2008 to 2010, a survey of natural weed hosts that could be reservoirs of TYLCV was performed in major tomato production areas of Korea. About 530 samples were collected and identified as belonging to 25 species from 11 families. PCR and Southern hybridization were used to detect TYLCV in samples, and replicating forms of TYLCV DNA were detected in three species (Achyranthes bidentata, Lamium amplexicaule, and Veronica persica) by Southern hybridization. TYLCV transmission mediated by Bemisia tabaci from TYLCV-infected tomato plants to L. amplexicaule was confirmed, and TYLCV-infected L. amplexicaule showed symptoms such as yellowing, stunting, and leaf curling. TYLCV from infected L. amplexicaule was also transmitted to healthy tomato and L. amplexicaule plants by B. tabaci. The rate of infection of L. amplexicaule by TYLCV was similar to that of tomato. This report is the first to show that L. amplexicaule is a reservoir weed host for TYLCV.     

Molecular cloning,expression analysis and functional characterization of interleukin-22 in So-iny mullet, Liza haematocheila

In the present study, interleukin-22 (IL-22) from So-iny mullet (Liza haematocheila) was identified, and its tissue expression in both healthy and Streptococcus dysgalactiae-infected fish was examined. The full length cDNA sequence of mullet IL-22 was 1070 bp, containing an open reading frame of 555 bp. The deduced amino acid sequence shared high similarity (45.1–67.9%) with IL-22 from other fish species. Mullet IL-22 also contained an IL-10 family signature and four cysteine residues that were well conserved in other vertebrate IL-22 molecules. Mullet IL-22 mRNA was highly expressed in kidney, moderately expressed in liver and gut, and relatively weakly expressed in spleen, and its expression was significantly up-regulated in all the examined tissues following S. dysgalactiae infection. Furthermore, recombinant mullet IL-22 protein was shown to promote the expression of β-defensin in the four tissues and to increase the survival rate of the fish infected with S. dysgalactiae. Our results suggest mullet IL-22 plays an important role in the immune defense against bacterial infection and has the potential to be used to treat bacterial diseases in fish.     

Comparative efficacy of two anesthetic agents in the Sobaity sea bream,Sparidentex hasta (Valenciennes 1830)

It is known that responses to the same anesthetic can vary considerably among different fish species. In this investigation, the efficacy of two anesthetic agents (clove powder and 2-phenoxyethanol) was compared in Sobaity sea bream, Sparidentex hasta (Valenciennes 1830). Induction and recovery times for S. hasta anesthetized with anesthetic agents were dose-dependent (P?<?0.05). The onset of individual phases of anesthesia and recovery times depended significantly on the concentration of the anesthetic used (P?<?0.05). An inverse exponential relationship was observed between concentrations of anesthetic and induction time, whereas exponential relationships were observed between concentrations and recovery times for both anesthetic agents evaluated. The lowest effective concentrations based on the efficacy criteria of complete anesthetic induction within 180 s and recovery within 300 s were determined to be 100 mg?L^?1 (induction time 1.92?±?0.10 min and recovery time 2.48?±?0.17 min) for clove powder and 200 μL?L^?1 (induction time 2.55?±?0.14 min and recovery time 5.66?±?0.62 min) for 2-phenoxyethanol. Clove powder was proven to be more effective, and the latter appears to meet many of the criteria of an ideal anesthetic for this fish species.     

<Emphasis Type="Italic">Kudoa unicapsula</Emphasis> n. sp. (Myxosporea: Kudoidae) a parasite of the Mediterranean mullets <Emphasis Type="Italic">Liza ramada</Emphasis> and <Emphasis Type="Italic">L. aurata</Emphasis> (Teleostei: Mugilidae)

A new multivalvulid myxozoan parasite, Kudoa unicapsula n. sp., is described from the intestinal mesentery, intestine and pyloric caeca of the thin-lipped grey mullet Liza ramada (Risso 1826) and the golden grey mullet L. aurata (Risso, 1810) from the Mediterranean coastal waters of Spain. It is characterized by the presence of elongated, rice corn-like white cysts of 0.47–0.56 × 0.18–0.38 mm, filled with tetracapsulate, slightly asymmetric spores, rectangular in apical view and tear-shaped in lateral view with four polar capsules of considerably different size and slightly unequal spore valves with rounded edges, overlapping each other on the apex of the spore. One large polar capsule includes a polar filament coiled in two to three turns, and the other three polar capsules, which are very small, posses only a rudimental filament. Both light and electron microscopy data showed that this species differs from all previously described Kudoa spp. with unequal polar capsules. The molecular analysis based on 18S and 28S ribosomal deoxyribonucleic acid DNA sequence data of K. unicapsula n. sp. indicates a close relationship and thus phylogenetic clustering together with K. trifolia, a myxozoan from the same host and the same geographical location.     

Infection of wild mullet (Mugil cephalus) with Myxobolus episquamalis in Korea

Wild mullet (Mugil cephalus) with white cysts on their scales were obtained from Yeosu on the south coast of Korea in 2009. Cyst-like plasmodia consisted of a large number of mature myxosporean spores and numerous sporogonic stages. Spores were oval-shaped in their front view, tapering anteriorly to a blunt apex, and lenticular in their lateral view. They measured 7.0 μm (6.2–7.6) in length, 5.2 μm (4.0–6.2) in width, and 4.9 μm (3.8–6.0) in thickness. Polar capsules contained a polar filament with five to six turns and measured 3.5 μm (2.5–4.5) in length and 2.0 μm (1.6–2.3) in width. Nucleotide sequences of the 18S rRNA gene of the myxosporean parasites in our study showed 99.8 % identity with Myxobolus episquamalis Egusa, Maeno and Sorimachi, 1990 from mullet in Tunisia. These results suggest that the Myxobolus sp. found on the scales of wild mullet is M. episquamalis. In the histopathological examination, spores were observed not only in the plasmodia on the scales, but also in the intestine, pancreas, heart, kidney, stomach, gill, skin, spleen, and liver, suggesting the possibility of the coinfection by different Myxobolus species.     

Antennal sensilla of the green bottle fly, Lucilia sericata (Meigen) (Diptera: Calliphoridae)

Lucilia sericata (Meigen) is a cosmopolitan synanthropic fly of forensic and medical importance, which can work as a mechanic vector of pathogens or cause myiasis of both human and sheep. As essential olfactory organs, antennae of adult L. sericata were examined with stereoscopic microscope, scanning electron microscope, and laser scanning confocal microscope. On antennal scape and pedicel, both microtirchiae and several bristles are detected, while another two structures, setiferous plaques and pedicellar buttons, are also found on the antennal pedicel. Seven subtypes of antennal sensilla are observed on antennal funiculus including one subtype of trichoid sensilla, two subtypes of basiconic sensilla, two subtypes of coeloconic sensilla, and two subtypes of sensory pits. Size and density of the former four types of sensilla on antennal funiculus are measured. Three distinctive sensillar characters of L. sericata are detected, which may contribute to greater olfactory sensitivity of this species and their wide distribution throughout the world. Unlike the common poreless pedicellar button with mechanoreceptor function, every pedicellar button in L. sericata is perforated by three pores, which might indicate potential chemoreceptor function of this structure. Besides, another unique feature is greater number of setiferous plaques in genus Lucilia than calliphorids of other genera. Expect for the common sensory pits with basiconic or basiconic-like sensilla in them, sensory pits filled with rarely described coeloconic-like sensilla are founded in L. sericata as well. After comparison with previous equivalent findings, the functions of these specific structures are discussed according to the life history of this calliphorid.     

Morphological and molecular characterization of Lecithochirium grandiporum (Digenea: Hemiuridae) infecting the European eel Anguilla anguilla as a new host record in Egypt

In the present study, the morphological and molecular characterization of Lecithochirium grandiporum, a digenetic trematode infecting the European eel Anguilla anguilla (Family (F): Anguillidae), were described for the first time from Burullus Lake, Kafr El-Sheikh Governorate, Egypt. Twenty-five out of 60 specimens (infection rate of 41.66 %) were found to be naturally infected. Infection was recorded as small worms attached to the inner wall of the intestine of host fish. Adult worms measured 1.59?±?0.20 (1.3–1.85)?mm long and 0.3?±?0.02 (0.29–0.48)?mm wide for everted specimens with a smaller oral sucker measuring 0.15?±?0.02 (0.13–0.18)?mm, and a larger ventral sucker which was 0.16?±?0.02 (0.14–0.25)?mm. Our results recorded morphological differences as smaller dimensions of different body parts and the smaller oral/ventral sucker ratio between Lecithochirium fusiforme and L. grandiporum. Also, the phylogenetic position of the worm was determined by molecular characterization of their 18 SSU rDNA. Results were compared with those of previously recorded species on the Gene Bank. It was found that the present species coincide with those belonging to genus Lecithochirium. Comparison of the nucleotide sequences and divergence showed that the SSU rDNA gene of this Lecithochirium species revealed 92 % sequence identity with L. fusiforme (accession no. DQ413192) differing in 26 nucleotides with lower divergence value. According to these results, this study indicated that the present species is recorded as L. grandiporum with accession no. KC166146 as a parasite with new host and locality records in Egypt.     

Infection and pathogenecity of Myroides odoratimimus (NIOCR-12) isolated from the gut of grey mullet (Mugil cephalus (Linnaeus, 1758))

Myroides sp. are gram negative aerobes and known for its oppurtunistic pathogenicity in humans. In the present study, Myroides odoratimimus isolated from the gut of Mugil cephalus showed potential infectivity to the experimental grey mullet and acted as an ultimate pathogen with significant symptoms. Furthermore, the inoculum isolated from the infected fishes were cultured and the selected colonies were reisolated and reinjected into healthy juveniles of M. cephalus. Characterizations of the re-isolated bacteria were the same as those of the isolated M. odoratimimus from naturally infected mullet. The median lethal dose (LD₅₀) of the bacteria was 3 × 10⁶ CFU fish^-1. In order to assay the accuracy of infection, the production of reactive oxygen species (ROS), the respiratory burst activity of blood leukocytes of mullet before and after challenge was measured, an indicator of the innate immune system. The mullet infection increased the respiratory burst activity and superoxide dismutase activity. In addition, the innate immune response of TLR 9 expression against M. odoratimimus infection and CpG ODN treatment in disease model, zebrafish confirms the M. odoratimimus infection and pathogenicity.     

Parasitization of invasive gobiids in the eastern part of the Central trans-European corridor of invasion of Ponto-Caspian hydrobionts

Four gobiid species, Babka gymnotrachelus, Neogobius melanostomus, Neogobius fluviatilis, and Proterorhinus semilunaris, were parasitologically studied in different localities of the Dnieper and Vistula river basins. The highest number of parasitic species was found in N. fluviatilis (35 taxa). The parasite fauna of N. melanostomus, B. gymnotrachelus, and P. semilunaris consists of 23, 22, and 15 taxa, respectively. The species accumulation curves show stable accumulation of parasite species by all four fish hosts along the studied part of the corridor, from the Dnieper Estuary to the Vistula River delta. The plot reveals also that the studied gobies lose the parasites common in the host native range and accept new parasites from the colonized area. In the case of N. melanostomus, it complies with the enemy release hypothesis, as the parasite load was low in the invaded area if compared to the native range. The three other alien gobies are vector for Gyrodactylus proterorhini in the Baltic basin. Moreover, populations of this alien monogenean tend to be more abundant in their new range in comparison with the Black Sea basin. In general, the number of parasite species in the colonized area was of the same rank as in the native one for N. fluviatilis, and even higher for B. gymnotrachelus. This results from accumulating new parasite species along the gobiid invasion route. In particular, the N. fluviatilis, B. gymnotrachelus, and P. semilunaris lost some of their native parasites and gained the local ones after entering the post-dam part of the Vistula River; it can be interpreted as a partial escape from parasites.     

The description and histopathology of Leptorhynchoides polycristatus n. sp. (Acanthocephala: Rhadinorhynchidae) from sturgeons, Acipenser spp. (Actinopterygii: Acipenseridae) in the Caspian Sea, Iran, with emendation of the generic diagnosis

Of the three known species of Leptorhynchoides Kostylew 1924, two are reported from North American fishes: Leptorhynchoides aphredoderi Buckner and Buckner 1976 and Leptorhynchoides thecatus (Linton 1891) Kostylew 1924. The third species, Leptorhynchoides plagicephalus (Westrumb 1821) Kostylew 1924, is commonly found in the Caspian and Black Sea from at least four species of sturgeons including Acipenser stellatus Pallas 1771 and the Acipenser nudiventris Lovetzsky 1828 from which Leptorhynchoides polycristatus n. sp. was found. No taxonomic work has been reported for L. plagicephalus for the last 90 years. L. polycristatus n. sp. can be readily confused with L. plagicephalus because of many superficial similarities. Such similarities include the general shape of the trunk, proboscis, and organ systems. However, L. polycristatus is clearly distinguished from the other three species primarily by having (1) 19–20 proboscis hooks per row; (2) the shortest hooks are anterior and the longest at the middle; the opposite is true in L. plagicephalus; (3) with a cuticular collar enveloping the base of the proboscis hooks; (4) the surface of its proboscis hooks is ribbed; (5) with a broad collar of multiple rectangular cuticular crests encircling the anterior end of the trunk; this is the only member of Leptorhynchoides with such a structure; (6) with many large ovoid uninucleated cells in the subcuticular layer of the trunk; (7) with paired glandular clusters near the male reproductive opening and of suction cup-like sensory structures on the bursa; (8) with dorsoventral ligament across the vagina; (9) cement glands are in a cluster of eight arranged in two horizontal tiers of four glands each; (10) with female gonopore near terminal; (11) with structures interpreted as possible microtriches on the surface of the trunk; (12) and with thinner eggs. L. polycristatus caused extensive histopathological damage to host intestinal layers. The armed proboscis invades and attaches to the host mucosa causing villi compression and necrosis of the epithelial lining with subsequent hemorrhaging and granulocyte migration. No encapsulation of the acanthocephalan is visible, and the worm can migrate deep into the smooth muscle layers of the muscularis extrema. The presence of L. polycristatus in the lumen of the host intestine obstructs and damages the absorbing surface of the host affecting the nutritional potential. Dead, necrotic host epithelial tissue and remnants of villi and crypts are visible.     

Phylogenetic position of Linguatula arctica and Linguatula serrata (Pentastomida) as inferred from the nuclear 18S rRNA gene and the mitochondrial cytochrome c oxidase subunit I gene

Genomic DNA was isolated from a Linguatula serrata female expelled from a dog imported to Norway from Romania and from four Linguatula arctica females collected from semi-domesticated reindeer from northern Norway and subjected to PCR amplification of the complete nuclear 18S rRNA gene and a 1,045-bp portion of the mitochondrial cytochrome c oxidase subunit I gene (cox1). The two species differed at two of 1,830 nucleotide positions (99.9 % identity) of the complete 18S rRNA gene sequences and at 102 of 1,045 nucleotide positions (90.2 % identity) of the partial cox1 sequences. The four isolates of L. arctica showed no genetic variation in either gene. The new cox1 primers may facilitate the diagnosis of various developmental stages of L. arctica and L. serrata in their hosts. In separate phylogenetic analyses using the maximum likelihood method on sequence data from either gene, L. arctica and L. serrata clustered with members of the order Cephalobaenida rather than with members of the order Porocephalida, in which the genus Linguatula is currently placed based on morphological characters. The phylogenetic relationship of L. arctica, L. serrata and other pentastomids to other metazoan groups could not be clearly resolved, but the pentastomids did not seem to have a sister relationship to crustaceans of the subclass Branchiura as found in other studies. A more extensive taxon sampling, including molecular characterisation of more pentastomid taxa across different genera, seems to be necessary in order to estimate the true relationship of the Pentastomida to other metazoan groups.     

Unicapsula species (Myxosporea: Trilosporidae) of Australian marine fishes, including the description of Unicapsula andersenae n. sp. in five teleost families off Queensland, Australia

A survey of the myxosporean fauna of Australian marine fishes revealed the presence of three previously unreported species of Unicapsula (Multivalvulida: Trilosporidae) from sites off Southeast Queensland, off Lizard Island on the Great Barrier Reef, Queensland, and from Jurien Bay in Western Australia. Morphometric data (spore, polar capsule and caudal appendage dimensions) combined with Bayesian inference and maximum likelihood analyses of small subunit (SSU) and large subunit (LSU) ribosomal DNA (rDNA) were used for species identification and to explore relationships among these taxa. The four species of Unicapsula for which DNA data are now available for comparative purposes (Unicapsula andersenae n. sp., Unicapsula pflugfelderi, Unicapsula seriolae and Unicapsula pyramidata) formed a well-supported monophyletic sister clade to the other major multivalvulidan group, the Kudoidae. The combined morphometric and genetic diagnostic approach identified an undescribed taxon, U. andersenae n. sp., from the muscle of Argyrosomus japonicus, Acanthopagrus australis and Eleutheronema tetradactylum off the Southeast Queensland coast and in Lutjanus russellii and Sillago ciliata off Lizard Island. Intra-specific variation within U. andersenae n. sp. varied from 2–4 (0.2–0.4 %) nucleotides over the SSU region to 2–20 (0.3–3.2 %) over the LSU region. Inter-specific variation between U. andersenae n. sp. and the other three species for which genetic sequence data are now available ranged from 15–66 (3–6.5 %) nucleotides over the SSU region to 103–120 (17.6–21.2 %) nucleotides over the LSU region. The host distribution observed here for U. andersenae n. sp. (five fish species from five different fish families) represents the broadest specificity known for a single species of Unicapsula. U. pyramidata Naidjenova & Zaika 1970, whose spore morphology and presence of caudal appendages immediately distinguish it from other species, was recovered from the nemipterid, Scolopsis monogramma, off Lizard Island. U. seriolae Lester 1982 is reported here from Yellowtail Kingfish, Seriola lalandi, from sites off Queensland and from Jurien Bay, Western Australia. Comparative genetic analyses also revealed that an unidentified species of Unicapsula from Epinephelus septemfasciatus off Japan whose rDNA sequence data are available on GenBank is consistent with U. seriolae. This suggests that U. seriolae may also exhibit low host specificity and may be distributed widely throughout the Indo-West Pacific region. In comparison to other myxozoan genera, it is clear that the species richness of Unicapsula spp. falls well below that displayed by either Ceratomyxa spp. or Kudoa spp. The discovery of a further new species of Unicapsula in Australia now brings the total worldwide number of formally described Unicapsula species to a modest 11. Nonetheless, this taxon remains of significant interest to commercial and recreational fisheries through the potential production of macroscopic pseudocysts in fish muscle and post-mortem muscle liquefaction, both of which can render fish fillets unpalatable and unmarketable.     

Coccidia (Apicomplexa: Eimeriidae) of elk (Alces alces) in Poland

Over a 4-year period, we analyzed 128 fecal samples from free-living elk (Alces alces L., 1758) to determine the prevalence of Eimeria infections and identify the species present. Two eimerian species were isolated including Eimeria alces and a morphotype resembling Eimeria catubrina. Overall, two samples from 128 samples collected were positive for Eimeria (prevalence?=?1.6 %), and the oocyst per gram, estimated with the use of the conventional McMaster quantitative technique, ranged from 50 to 100. Also, E. alces has been found in Lithuania and Belarus and is the only known species of eimerian to infect elk. E. catubrina is a parasite typically infecting roe deer (Capreolus capreolus L., 1758). This is the first report of Eimeria spp. in elk in Poland. Results of our investigation indicate that elk may become infected with an eimerian species that is typical for roe deer, but this requires further investigation.     

Study of Myxosporea (Myxozoa), infecting worldwide mullets with description of a new species

Existing data on Myxozoa parasites infecting mullets were reviewed. The validity of nine species names was updated. Sixteen species were registered during analysis of original material collected in the Mediterranean, Black, Azov, and Japan Seas in 2004–2005. A new bivalvulid myxozoan parasite, Myxobolus adeli n. sp., was described from the inner organs of the golden grey mullet Liza aurata (Risso, 1810) collected in the Mediterranean (Ebro Delta, Spain), Black Sea (Kerch Strait, Ukraine), and Azov Sea (Genichesk, Ukraine) coastal waters. It is characterized by the presence of elongated, spindle-like cysts 0.5–1.3 mm in size, filled with wide transverse-oval spores about 6.2?×?7.2?×?4.6 μm in size, with two equal polar capsules measuring about 3.0?×?1.8 μm and short polar filament, turned into four coils. The obtained data show that this species differs from all previously described Myxobolus spp. with equal polar capsules. Comparative study of Myxobolus spp. recorded in worldwide mullets indicates a close relationship with M. adeli n. sp. and Myxobolus improvisus Isjumova, 1964 registered in mullets. Probably, the last species includes representatives of some different species, infecting freshwater and marine hosts.     

Trematodes from Red Sea fishes: Pachycreadium lethrini sp. nov. (Opecoelidae Ozaki, 1925) and Pseudometadena aegyptensis sp. nov. (Cryptogonimidae Ward, 1917), with a review of their genera

Specimens of the fishes Lethrinus nebulosus Forsskål (Lethrinidae) and Diplodus noct Valenciennes (Sparidae) were caught in the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt. Ten (33%) and 12 (24%) of these fishes, respectively, were found to harbour intestinal trematodes. L. nebulosus was parasitised by Pachycreadium lethrini sp. nov. (Opecoelidae) and D. noct by Pseudometadena aegyptensis sp. nov. (Cryptogonimidae). P. lethrini sp. nov. is unique in having distinctly unequal testes, contiguous gonads arranged obliquely in the right side of hindbody and a small egg size. However, it differs from each of the other three species of the genus in several other features: from P. gastrocotylum (Manter, 1940) Manter, 1954 in having a smaller sucker ratio and vitelline follicles terminating anteriorly at the level of intestinal bifurcation; from P. carnosum (Rudolphi, 1819) Cortini et Ferretti, 1959 in having a smaller body, a smaller sucker ratio, a genital pore situated ventrally to the anterior border of pharynx, a pretesticular ovary and vitelline follicles extending anteriorly to the level of intestinal bifurcation; and from P. lerneri Sogandares-Bernal, 1959 in having a larger body, a smaller sucker ratio and an unlobed ovary. P. angolensis Aleshkina et Gaevskaya, 1985 is considered an invalid species in Pachycreadium. P. aegyptensis sp. nov. is similar to P. celebesensis Yamaguti, 1952, but mainly differs in having a larger pharynx, a much shorter oesophagus, extensive vitelline acini and a shorter seminal vesicle. Pachycreadium Manter, 1954 and Pseudometadena Yamaguti, 1952 are briefly reviewed.     

Biochemical identification of cutaneous leishmanias by analysis of kinetoplast DNA. I. Ultrastructural and buoyant density analysis

Ultrastructural analysis has been carried out on three Leishmania isolates which are proven causal agents of human cutaneous Leishmaniasis, L. tropicamajor, L. aethiopica and a unidentified species, Leishmania SP48. No significant differences in submicroscopic morphology have been found in thin-sectioned organisms from the three isolates. Extensive plate cristae have been observed within the mitochondria and connections between the rim of the kinetoplast nucleoid and the inner mitochondrial membrane noted.Kinetoplast DNA (kDNA) has been isolated from these isolates and from L. tarentolae and examined by protein monolayer spreading and darkfield electronmicroscopy. The basic molecular arrangement of isolated kDNA in the form of 5 μm networks of 0.28-0.3 μm mini-circles with long looped DNA in the interior and at the periphery of networks is similar in all isolates. Minor differences between L. aethiopica and SP48 compared with L. tropicamajor have been observed. The kDNAs of L. aethiopica and SP48 are identical morphologically.Buoyant density analysis has shown that kDNA from L. aethiopica and SP48 have identical values and these are different from the value for L. tropicamajor. The finding of similar buoyant densities for kDNA from L. tropicamajor and L. tarentolae also imply a sequence homology by this criteria which is refuted by the results given in the following paper.The results given in this and the following paper (Arnot, D.E. and Barker, D.C. (1981) Mol. Biochem. Parasitol. 3, 47–56 indicate that the unknown Leishmania SP48 is very closely related to, if not identical with, L. aethiopica. This finding is consistent with the clinical and ecological facts known for the organism SP48.