Indo-Pacific Species Research Articles

Short and Long Term Toxicity of Crude Oil and Oil Dispersants to Two Representative Coral Species

Oil dispersants, the tool of choice for treating oil spills in tropical marine environments, is potentially harmful to marine life, including reef corals. In a previous study, we found that dispersed oil and oil dispersants are harmful to soft and hard coral species at early life stages. In this broader study, we employed a "nubbin assay" on more than 10 000 coral fragments to evaluate the short- and long-term impacts of dispersed oil fractions (DOFs) from six commercial dispersants, the dispersants and water-soluble-fractions (WSFs) of Egyptian crude oil, on two Indo Pacific branching coral species, Stylophora pistillata and Pocillopora damicornis. Survivorship and growth of nubbins were recorded for up to 50 days following a single, short (24 h) exposure to toxicants in various concentrations. Manufacturer-recommended dispersant concentrations proved to be highly toxic and resulted in mortality for all nubbins. The dispersed oil and the dispersants were significantly more toxic than crude oil WSFs. As corals are particularly susceptible to oil detergents and dispersed oil, the results of these assays rules out the use of any oil dispersant in coral reefs and in their vicinity. The ecotoxicological impacts of the various dispersants on the corals could be rated on a scale from the least to the most harmful agent, as follows: Slickgone > Petrotech > Inipol = Biorieco > Emulgal > Dispolen.

Structure and Absolute Stereochemistry of Syphonoside, a Unique Macrocyclic Glycoterpenoid from Marine Organisms

The glycoterpenoid syphonoside (1) is the main secondary metabolite of both the marine mollusk Syphonota geographica and the sea-grass Halophila stipulacea, two Indo-Pacific species migrated to the Mediterranean Sea through the Suez Canal. The structure and the absolute stereochemistry of 1, which displays unique structural features, has been accomplished by using a combination of spectroscopic techniques, degradation reactions, and conformational analysis methods. Compound 1 was able to inhibit high density induced apoptosis in a number of human and murine carcinoma cell lines.

A critical review of records of alien marine species from the Maltese Islands and surrounding waters (Central Mediterranean)

An updated list of alien marine species recorded from the Maltese Islands and surrounding waters, compiled from scientific and ‘grey’ literature and from authenticated unpublished reports to the authors, is presented. The listed species are classified in one of four categories as regards establishment status: established, casual, invasive and questionable. Doubtful records are listed as ‘?’. A total of 48 species, including nine dubious ones, are included in the list. Of the accepted records, 64% are established, of which 15.4% are invasive, 18% are casual and 18% are questionable. The most represented groups are molluscs (14 species), fish (13 species) and macrophytes (10 species). Six species are classified as invasive in Maltese waters: Lophocladia lallemandii, Womersleyella setacea, Caulerpa racemosa var. cylindracea, Percnon gibbesi, Fistularia commersonii and Sphoeroides pachygaster; impacts of some of these species on local ecosystems are discussed. Since the early 1900s, there has been an increasing trend in the number of alien marine species reported from the Maltese Islands. Transportation via shipping and in connection with aquaculture, as well as the range expansion of Lessepsian immigrants, appear to be the most common vectors for entry, accounting for 20%, 11% and 32% respectively of the alien species included in this review. The general warming trend of Mediterranean waters and increasing marine traffic may be facilitating the spread of warm-water Atlantic and Indo-Pacific species to the central Mediterranean, including the Maltese Islands.

A New Gerreid Fish Species and Redescription of Gerres maldivensis Regan, 1902 from the Indian Ocean (Perciformes: Gerreidae)

Abstract A new gerreid fish species, Gerres mozambiquensis, is described on the basis of a holotype and one paratype from Larde Estuary, southern Nampura, Mozambique. The species is characterized by the following unique combination of characters: relatively deep body (greatest depth 46–47% SL); robust second anal-fin spine (greatest width of second spine/greatest width of third spine = 1.7–1.8); three supraneural bones configuration (0/0/0+2/); dorsal fin with nine spines and ten rays; lateral-line scales 43 or 44; 4 or 4½ scales between fifth dorsal-fin spine base and lateral line; caudal-fin lobes short, the tips rounded with growth; and six to eight indistinct dark vertical bars (bar width about half pupil diameter) on lateral surface of body. Gerres maldivensis Regan, 1902, formerly considered a junior synonym of G. erythrourus (Bloch, 1791) ( = G. abbreviatus), is reinstated as a valid Indo-Pacific species. It is characterized by body depth 43% SL, approximately eight faint dark vertical bars on b...

The Indian scad (<i>Decapterus russelli</i>), (Osteichtyes: Carangidae), a new Indo-Pacific fish invader of the eastern Mediterranean

The Indian scad, Decapterus russelli , is recorded for the first time from the Mediterranean. The presence of this Indo-Pacific species on the Mediterranean coast of Israel is evidently due to migration from the Red Sea via the Suez Canal. The collection of six specimens in the Mediterranean suggests that this species is well established in the Levant.

Finding of Myripristis botche (Holocentridae) in coastal waters of south Vietnam

The holocentrid fish Myripristis botche was first described by Cuvier (Cuvier, 1829; Cuvier and Valenciennes, 1829) from the Indian Ocean off the Coromandel Coast of Hindustan. Later, Weber and Beaufort (1929) reduced this name, in doubt, to the synonym of M. murdjan (Forsskal). In the revision of the genus Myripristis made by Greenfield (1974), the name botche is not even mentioned as a synonym of any species. The validity of M. botche was recovered by Soetikno (1975) who provided a detailed description of this species from the Northern Pagai Island (the Mentawai Islands, the Indian Ocean). In the new revision of the Indo-Pacific species of the genus Myripristis , Randall and Greenfield (1996) once again confirmed the validity of the species under consideration with an extended justification of this fact. Currently M. botche is known from a few findings in the tropical parts of the Indian Ocean and the western part of the Pacific Ocean. In June 2003, while conducting underwater studies under the framework of the program of the Tropical Center of the Russian Academy of Sciences, M. botche was discovered by the first author in Nha Trang Bay, south of the Noc Island (South Vietnam, Khanh Hoa Province), at a depth of 23 m. Two individuals of the considered species were found in the daytime (about 3 p.m.) under the margin of a massive mushroom coral Porites sp. having a diameter of 1.8 m (figure). A onemeter encrusting colony of coral Favia sp. was situated on the bottom near the Porites sp. The margins of the coral Porites sp. were thinned as a comb; they were underlain by deep pockets extending inward from the colony and formed as a result of the erosion of the skeletal material of the colony. The coral was approximately 60‐80 m remote from the margin of the rock socle of the Noc Island and was situated on a mediumgrained weakly silted coral sand with inclusions of the fragmentary material. The bottom at this place was even and had a slight slope, gradually lowering further down to a depth of 50 m. Larger fragments of dead corals and rocky ground where low colonies of

Phylogenetic relationships of some common Indo-Pacific snappers (Perciformes: Lutjanidae) based on mitochondrial DNA sequences, with comments on the taxonomic position of the Caesioninae

The phylogenetic relationships of 27 species of common Indo-Pacific snappers (Lutjanidae) were explored using the 16S ribosomal RNA and cytochrome b mitochondrial genes with minimum evolution, maximum parsimony, maximum likelihood and Bayesian inference analyses. Included were species representing four subfamilies, the Caesioninae, Etelinae, Paradicichthyinae, and Lutjaninae. Members of the closely related families Haemulidae, Lethrinidae, Nemipteridae and Sparidae, were included for outgroup comparisons and to explore the relationships between the Haemuloidea, Lutjanoidea and Sparoidea. Monophyly of the Lutjanidae was resolved. The Caesioninae was nested within the Lutjaninae, supporting the recent view that the Caesionidae should be treated as a synonym of the Lutjanidae. The subfamilies Etelinae and Paradicichthyinae were resolved as sister taxa to the remainder of the Lutjanidae, which corroborates previous cladistic analyses conducted to determine relationships of lutjanid subfamilies. Bayesian inference and maximum likelihood analyses suggest that Macolor is the sister taxon to the Caesioninae and may represent a transitional form between the Lutjaninae and Caesioninae. Three species of Western Atlantic lutjanids, Lutjanus campechanus, L. synagris, and Rhomboplites aurorubens, were included in the analyses to examine their relationships to Indo-Pacific species; they formed a well-supported clade nested within Pacific lutjanines suggesting that Atlantic species of Lutjaninae are derived from an Indo-Pacific lineage. Results of our molecular phylogenetic analyses are congruent with the general morphology and external colouration of the resolved groups of species of Lutjanus. The “black spot” complex containing L. fulviflamma, L. monostigma, and L. russelli was resolved with strong support, and had L. carponotatus nested within. The morphology of L. carponotatus suggests a close relationship to this group, and the lack of the black spot near the lateral line below the soft dorsal fin is possibly a secondary loss. As expected, the “blue-lined” species, L. kasmira and L. quinquelineatus, formed a strongly supported clade. Lutjanus bohar and L. gibbus, both distinctly red, long-lived fish that often accumulate large quantities of ciguatera toxin in their tissues, were resolved as sister taxa.

A revision of Cladophoropsis Børgesen (Siphonocladales, Chlorophyta)

F. Leliaert and E. Coppejans. 2006. A revision of Cladophoropsis Børgesen (Siphonocladales, Chlorophyta). Phycologia 45: 657–679. DOI: 10.2216/06-07.1.A reassessment of the genus Cladophoropsis results in the recognition of six morphospecies: C. macromeres, C. magna, C. membranacea, C. philippinensis, C. sundanensis and C. vaucheriiformis. The emended genus Cladophoropsis is characterized by mat- or cushion-forming plants attached to the substratum by tenacular cells or by rhizoids that sprout from the proximal pole of the basal cells or are formed in any part of the thallus, cell division by centripetal wall ingrowths or occasionally segregative, cells producing a single lateral but older cells occasionally producing secondary laterals, cross walls at the base of the laterals either absent or their formation markedly delayed and reinforcement of the thallus by entangling of the filaments or by anastomosis of adjacent filaments by tenacular cells. The different species are distinguished from each other based on thallus structure, mode of cell division, organization of branch systems, mode of thallus attachment and reinforcement, shape and dimensions of the cells and shape of the crystalline cell inclusions. Twenty Cladophoropsis species are excluded from the genus, including the widely distributed Indo-Pacific species C. herpestica and C. javanica, which have been found to be unrelated to other Cladophoropsis species but instead allied with species of the Cladophora section Longiarticulatae. Phylogenetic studies based on molecular data have furthermore demonstrated that Cladophoropsis is closely related to Boodlea, Phyllodictyon, Struveopsis, Struvea and Chamaedoris and that the genus probably does not form a natural group within this genus complex. Morphologically this can be illustrated by a number of Cladophoropsis species (e.g. C. magna and C. membranacea) crossing generic boundaries by sharing common features with Chamaedoris, Boodlea, Phyllodictyon and Struvea. For the benefit of taxonomic stability, Cladophoropsis is presently maintained, awaiting additional molecular evidence.

Proboscis ornamentation as a diagnostic character for the Anoplodactylus californicus-digitatus complex (Arthropoda: Pycnogonida) with an example from the Anoplodactylus eroticus female

Females of the Indo-Pacific species Anoplodactylus eroticus (Arthropoda: Pycnogonida: Phoxichilidiidae) are described for the first time. The presence of peculiar ventral outgrowths or protuberances on the female proboscis of A. eroticus and 13 other Anoplodactylus species motivates an evaluation of a californicus-digitatus complex, based on external morphology and species distribution. The anatomy and development of proboscis protuberances is assessed using scanning electron microscopy (SEM), Nomarski optics, and flourescence microscopy. External morphology of A. eroticus is compared to that of apparently related species. An identification key for the 14 species of Anoplodactylus with females bearing a proboscis with ventral protuberances is provided here as an identification tool.

New Species of Shallow Water Scorpionfish (Scorpaenidae: Scorpaena) from the Central Coast of Western Australia

A new species of scorpionfish, Scorpaena gasta, is described on the basis of five specimens collected from the warm temperate central coast of Western Australia, eastern Indian Ocean, at depths of 3–7 m. Scorpaena gasta is most similar to a Western Australian species, S. sumptuosa. The two species are distinguished from other IndoPacific species of Scorpaena by the following combination of characters: lateral surface of maxilla with a distinct longitudinal ridge; relatively thick skin with numerous small sensory pores covering nearly the entire predorsal area to near the first pored lateralline scale; anteroventral surface of lower jaw with one or two pairs of slender tentacles in ventral view. Scorpaena gasta and S. sumptuosa are separated by four meristic, several morphometric, and color features. Scorpaena gasta is a small species (smallest mature female 67.4 mm SL; largest known specimen 83.6 mm SL), whereas S. sumptuosa is a relatively large species, attaining at least 241 mm SL.

A new wobbegong shark, Orectolobus hutchinsi n. sp. (Orectolobiformes: Orectolobidae) from southwestern Australia

Orectolobus hutchinsi n. sp.. is a moderate-sized wobbegong shark found in shallow continental shelf habitats off Western Australia. It occurs from Coral Bay (near North West Cape) south to Groper Bluff (west of Bremer Bay) in depths of 9–106 m where it is caught as by-catch of local gillnet, longline, rock lobster and recreational fisheries. It is sympatric with two other commercial wobbegong species, Orectolobus maculatus and O. ornatus, but differs from these and other IndoPacific species in having the combination of a few unbranched dermal lobes, relatively tall dorsal fins, no warty tubercles on the back of adults, and dark brown corrugated saddles without white spots and blotches. Some details of its biology are also provided.

A revision of the labrid fish genus Bodianus with descriptions of seven new species

The genus Bodianus (family Labridae), distributed in tropical and warm temperate waters of the three major oceans, comprises at least 43 species, eight of which are described here as new. On the basis of phylogenetic analysis, 10 subgenera are recognized, three taking new names. The subgenera include: the Western Pacific Priobodianus n.subgen. with the two species B. cylindriatus and B. thoracotaeniatus; the Indo-West Pacific Trochocopus with the eight species B. bimaculatus, B. izuensis, B. masudai, B. neopercularis n.sp. (Marshall Islands), B. opercularis, B. sanguineus, B. sepiacaudus n.sp. (Indonesia and Pacific Line Islands) and B. tanyokidus; the monotypic Eastern Atlantic Pseudolepidaplois with B. scrofa; the antitropical Verreo with the six Pacific species B. bathycapros n.sp. (Hawaiian Islands), B. flavifrons, B. flavipinnis, B. frenchii, B. oxycephalus and B. unimaculatus, and the southwestern Australian B. vulpinus; the Indo-West Pacific Peneverreo n.subgen. with the four species B. leucosticticus, B. paraleucosticticus n.sp. (Papua New Guinea, New Caledonia and Rarotonga), B. rubrisos n.sp. (Japan, Taiwan and Indonesia) and B. trilineatus; the Indo-Pacific Paralepidaplois n.subgen. with the three allopatric species B. diana (Indian Ocean), B. dictynna n.sp. (Western Pacific) and B. prognathus; the Indo-Pacific Lepidaplois with the three species B. axillaris, B. mesothorax and B. neilli; the monotypic Indo-Pacific Euhypsocara with B. anthioides; Diastodon with the eight Indo-Pacific species B. albotaeniatus, B. bilunulatus, B. busellatus n.sp. (south central Pacific), B. loxozonus, B. macrognathos, B. macrourus, B. perditio, and B. solatus n.sp. (western Australia), and the Eastern Atlantic B. speciosus; and, Bodianus with the Atlantic B. insularis, B. pulchellus and B. rufus, and the Eastern Pacific B. diplotaenia and B. eclancheri. Separate keys to species occurring in the Indo-Pacific and Atlantic-eastern Pacific regions are provided.

Acute Toxicity of Ammonia to Penaeus semisulcatus Postlarvae in Relation to Salinity

Stocking densities of cultured penaeid shrimp have been intensified because of the limited availability of land for pond construction. In an intensive culture system, ammonia is the most common toxicant resulting from nitrogen excretion by cultured animals and mineralization of unconsumed feed and feces (Lin and Chen 2003). In decapod crustaceans, nitrogen is excreted mainly as ammonia (60–70% of total ammonia) (Lee and Chen 2003). Concentrations of total ammonia-nitrogen (TAN) increase directly with culture period and might reach as high as 46 mg TAN/L in intensive grow-out ponds (Chen and Lin 1992). Accumulation of ammonia-nitrogen in pond water may deteriorate water quality, reduce growth, increase oxygen consumption, alter concentrations of hemolymph protein and free amino acid levels, and even cause high mortality (Chen and Lin 1992; Chen et al. 1994). TAN is composed of NH3-N (unionized ammonia) andNH4+ (ionized ammonia) (Losordo et al. 1992; Masser et al. 1992). It is the unionized form that is most toxic to aquatic organisms as it can readily diffuse through cell membranes and is highly soluble in lipids (Chin and Chen 1987; Frias-Espericueta et al. 1999). There is an equilibrium between NH4+ and NH3-N in the water. This equilibrium is affected by pH, temperature, and salinity. The higher the pH and temperature, the higher the proportion of NH3-N, while an increase in salinity will lead to lower proportions of the unionized form, hence the toxicity of the TAN to aquatic animals (Losordo et al. 1992;Masser et al. 1992; Sampaio et al. 2002). A number of studies have been conducted on the lethal effects of ammonia at various life stages of penaeid shrimps, such as Penaeus chinensis (Chen and Lin 1992), P. monodon (Chen and Lei 1990), P. paulensis (Ostrensky and Wasielesky 1995), P. penicillatus (Chen and Lin 1991), P. semisulcatus (Wajsbrot et al. 1990), and Metapenaeus ensis (Nan and Chen 1991). However, little information is available on the lethal effect of ammonia at different salinity levels for penaeid shrimps. Chen and Lin (1992) and Lin and Chen (2003) studied ammonia toxicity in P. chinensis and Litopenaeus vannamei at three different salinity levels, but no results have been reported for other penaeid species. Green tiger shrimp (P. semisulcatus) is an Indo-Pacific species, distributed along the coast of the Eastern Mediterranean, and is one of the most important commercial species in this part of the world. This species is less tolerant to low salinity levels (Soyel and Kumlu 2003), and knowledge of the effects of ammonia toxicity at various salinity regimes that may be confronted during the culture and overwintering periods in the subtropical areas is of importance for the farmers. This paper provides information on acute toxicity of ammonia to juveniles of this shrimp species at six different salinity levels (15, 20, 25, 30, 35, and 40 ppt).

Nomenclature and type material of the marine gastropod Euplica scripta (Lamarck, 1822) (Sorbeoconcha: Buccinoidea: Columbellidae)

This contribution stabilises the species-level nomenclature of a very common and widespread IndoPacific species of dove snail (Columbellidae). This species has had a confused nomenclature through uncertainty over secondary homonymy. Despite bearing the same epithet, the scientific names Murex scriptus Linnaeus, 1758 and Colombella (sic) scripta Lamarck, 1822 are not, and never have been, secondary homonyms because the species they represent are located in separate genera (and subfamilies) in the Columbellidae (i.e., presently in Mitrella (Pyreninae) and Euplica (Columbellinae), respectively) and the Lamarckian epithet has never been formally or intentionally replaced on the grounds of homonymy. A case of secondary homonymy would only arise in the future if an author considered them congeneric which, given the current trend for greater generic splitting in the family to accommodate monophyletic clades, appears highly unlikely. In order to settle the nomenclature unambiguously and avoid possible future taxonomic difficulties with species related to E. scripta i.e., E. varians (G.B. Sowerby 1, 1822), E. bidentata (Menke, 1843) and E. borealis (Pilsbry, 1904), a specimen from the Philippine Islands is herein selected as neotype for both Columbella scripta and C. versicolor G.B. Sowerby 1, 1832, the most frequently used junior synonym, in the absence of any definite syntypes. In other words, the names Colombella scripta Lamarck and Columbella versicolor G.B. Sowerby 1 are henceforth objective synonyms.

Indo-Pacific gastropod species in the Levantine and Aegean Seas

The present study reports the occurrence of three Indo-Pacific gastropod species at new localities in the Mediterranean Sea. Chromodoris quadricolor was recorded on the 29 May 2004 in the eastern Medi-terranean, which is the third report of the species from the Mediterranean Sea. Finella pupoides and Syrnola fasciata are collected from the several sites in the Aegean Sea between 1997 and 2002. The morphological, ecological and distributional characteristics of these species are described.

Shallow mtDNA Coalescence in Atlantic Pygmy Angelfishes (Genus Centropyge) Indicates a Recent Invasion from the Indian Ocean

Pygmy angelfishes (genus Centropyge) are widespread and species-rich in the Indo-Pacific, but only three species are recognized in the Atlantic: Centropyge resplendens on the Mid-Atlantic Ridge, Centropyge argi in the Caribbean, and Centropyge aurantonotus in Brazil and the southern Caribbean. Atlantic species are distinguished only by color patterns and are very similar to Centropyge acanthops (Cac) in the western Indian Ocean, raising the possibility that pygmy angelfish recently invaded the Atlantic Ocean via southern Africa. To test this zoogeographic hypothesis, we compared a 454-bp segment of the mitochondrial DNA (mtDNA) control region among pygmy angelfishes of the subgenus Xiphypops, which includes the three Atlantic species, the Indian Ocean species, and an Indo-Pacific species [Centropyge fisheri (Cfi)]. The Indian Ocean species Cac is closest to the Atlantic species (d = 0.059) relative to Cfi (d = 0.077). The mtDNA genealogy indicates a colonization pathway from the Indian Ocean directly to the West Atlantic, followed by at least two waves of dispersal to the Mid-Atlantic Ridge. The gene tree for the three Atlantic species is polyphyletic, raising questions about taxonomic assignments based on color pattern. Mismatch distributions place Atlantic founder events and population expansions at about 250,000-500,000 years ago. Estimates of effective female population sizes from mismatch and coalescence analyses are consistent with founder events by tens of individuals in the western Atlantic, followed by expansions to several million individuals.

Heteropod molluscs from waters around the Selvagens Islands (Gastropoda: Carinarioidea)

Heteropod molluscs were removed from zooplankton samples collected during cruise TFMCBMSV/00 to the Selvagens Islands. A total of 48 specimens were obtained. Among the eleven species of heteropods identified, Atlanta meteori was previously regarded as an Indo-Pacific species and was recorded here for the first time from the Atlantic Ocean. The second, Atlanta selvagensis, is a new species. The species records are compared with those obtained previously from the nearby waters of the Canary Islands

Preliminary Molecular and Morphological Study of the Calappa Lophos Species Group (Decapoda: Brachyura: Calappidae)

Abstract The systematics of the Calappa lophos species group is clarified using morphological and molecular data. The phylogeny of some Indo-Pacific species of Calappa is discussed. Two species, C. quadrimaculata Takeda and Shikatani, 1990, and C. guerini (Brito-Capello, 1871), previously synonymised with C. lophos (Herbst, 1782), are shown to be valid species using morphological and molecular data. A new species in the group, C. acutispina, is described from Madagascar. The usefulness of Bayesian inference in elucidating the phylogenetic relationships of some of the species of Calappa based on partial cytochrome oxidase I (COI) sequences is examined.

Two new species of Paguristes sensu stricto (Decapoda: Anomura: Paguroidea: Diogenidae) and a review of Paguristes pusillus Henderson

A new species of the hermit crab genus Paguristes, sensu stricto, Paguristes alcock n. sp., is described and illustrated from materials collected in Australia, Indonesia and the Philippine Islands. It is proposed that this taxon, or a species identified simply as Paguristes sp. by Lewinsohn (1969) in his monograph of Red Sea Anomura, may be conspecific with the species incorrectly referred by Alcock (1905) and several subsequent carcinologists to Paguristes ciliatus Heller, 1862. Lewinsohn subsequently re-identified his material of Paguristes sp. as Paguristes ciliatus sensu Alcock, 1905 and P. pusillus Henderson, 1896. Alcock’s single specimen of P. ? ciliatus from the Persian Gulf was not available for reexamination. Lewinsohn’s specimens however, have been reviewed and compared with the present authors Indo-Pacific species and with a specimen identified by Henderson as P. pusillus. Lewinsohn’s Red Sea specimens are described and illustrated herein as P. lewinsohni n. sp., as are the specimens identified as P. pusillus by Thompson (1943) from the John Murray Expedition. An illustrated description of P. pusillus is also provided to facilitate recognition of these superficially similar species. Paguristes pusillus zhejiangensis Wang & Tung, 1982 is considered to be a distinct taxon, not a subspecies of P. pusillus, and is herein elevated to full specific rank.

KUDOA IWATAI (MYXOSPOREA: MULTIVALVULIDA) IN WILD AND CULTURED FISH IN THE RED SEA: REDESCRIPTION AND MOLECULAR PHYLOGENY

Gilt-head sea bream, Sparus aurata L., the Mediterranean's most important mariculture species, has been cultured for the last 30 yr in Eilat (Israeli Red Sea). Kudoa sp. was the first myxosporean parasite reported from this species. In recent years, an increase in prevalence in both land-based and sea-cage facilities in Eilat has been observed. Infections with the same Kudoa species appeared in cultured European sea bass Dicentrarchus labrax (L.) and grey mullet Mugil cephalus in the same farms, as well as in 10 species of wild Red Sea reef fish, indicating that Kudoa sp. is not fastidious with regard to its host. All affected species displayed 1- to 2-mm (up to 5 mm) whitish, spherical, or oval polysporous plasmodia. The parasite established multiple site infections, most commonly in the muscles and intracranial adipose tissue of the brain and eye periphery. Other sites were subcutaneous adipose tissue, nerve axons, mouth, eye, mesenteries, peritoneum, swim bladder, intestinal musculature, heart, pericardium, kidney, and ovary. On the basis of spore morphology, the parasite was identified as Kudoa iwatai Egusa and Shiomitsu, 1983. Ultrastructural features were comparable to those of previously studied Kudoa species. The 18S rDNA from 7 Red Sea isolates was sequenced and compared with the sequence of the same gene from K. iwatai isolated from cultured red sea bream, Pagrus major, in Japan. The phylogenetic position of K. iwatai within the genus was determined using sequence analysis of all related taxa available in GenBank. The 3 isolates of K. iwatai clustered together on a newly formed, highly supported clade. The Red Sea strain of K. iwatai is apparently native to the region. In the absence of records of this Kudoa sp. from the extensive Mediterranean sea bream and sea bass production industries, introduction with its Mediterranean hosts seems unlikely. Therefore, we conclude that K. iwatai is an Indo-Pacific species that, in the Red Sea, has extended its host range to include the allochthonous gilt-head sea bream, European sea bass, and grey mullet.