A Fish Assemblage from the Middle Eocene from Libya (Dur At-Talah) and the Earliest Record of Modern African Fish Genera

In the early nineteen sixties, Arambourg and Magnier found some freshwater fish (i.e., Polypterus sp., Siluriformes indet. and Lates sp.) mixed with marine members in an Eocene vertebrate assemblage at Gebel Coquin, in the southern Libyan Desert. This locality, aged ca 37–39Ma and now known under the name of Dur At-Talah, has been recently excavated. A new fish assemblage, mostly composed of teeth, was collected by the Mission Paléontologique Franco-Libyenne. In this paper, we describe freshwater fish members including a dipnoan (Protopterus sp.), and several actinopterygians: bichir (Polypterus sp.), aba fish (Gymnarchus sp.), several catfishes (Chrysichthys sp. and a mochokid indet.), several characiforms (including the tiger fish Hydrocynus sp., and one or two alestin-like fish), and perciforms (including the snake-head fish Parachanna sp. and at least one cichlid). Together with the fossiliferous outcrops at Birket Qarun in Egypt, the Libyan site at Dur At-Talah reduces a 10-Ma chronological gap in the fossil record of African freshwater fish. Their fish assemblages overlap in their composition and thus constitute a rather homogenous, original and significant amount of new elements regarding the Paleogene African ichthyofauna. This supports the establishment of the modern African freshwater fish fauna during this time period because these sites mostly contain the earliest members known in modern genera.     

Parasites of native and nonnative fishes of the Little Colorado River, Grand Canyon, Arizona

A 2-yr, seasonal, parasitological study of 1,435 fish, belonging to 4 species of native fishes and 7 species of nonnative fishes from the lower Little Colorado River (LCR) and tributary creeks, Grand Canyon, Arizona, yielded 17 species of parasites. These comprised 1 myxozoan (Henneguya exilis), 2 copepods (Ergasilus arthrosis and Lernaea cyprinacea), 1 acarine (Oribatida gen. sp.), 1 piscicolid leech (Myzobdella lugubris), 4 monogeneans (Gyrodactylus hoffmani, Gyrodactylus sp., Dactylogyrus extensus, and Ligictaluridus floridanus), 4 nematodes (Contracaecum sp., Eustrongylides sp., Rhabdochona sp., and Truttaedacnitis truttae), 3 cestodes (Bothriocephalus acheilognathi, Corallobothrium fimbriatum, and Megathylacoides giganteum), and 2 trematodes (Ornithodiplostomum sp. and Posthodiplostomum sp.). Rhabdochona sp. was the only adult parasite native to the LCR. Infection intensities of Ornithodiplostomum sp. and B. acheilognathi were positively correlated with length of the humpback chub Gila cypha. Adult helminths showed a high degree of host specificity, except B. acheilognathi, which was recovered from all fish species examined but was most abundant in cyprinids. Abundance of B. acheilognathi in the humpback chub was highest in the fall and lowest in the summer in both reaches of the LCR. There was no major taxonomic difference in parasite assemblages between the 2 different reaches of the river (LC1 and LC2). Parasite community diversity was very similar in humpback chub, regardless of sampling site or time. The parasite fauna of the LCR is numerically dominated by B. acheilognathi and metacercariae of Ornithodiplostomum sp. The richest and most diverse component community occurred in a nonnative species, the channel catfish Ictalurus punctatus, but infracommunity species richness was highest in a native host, humpback chub.     

First record of Lipaphis pseudobrassicae Davis (Hemiptera: Aphididae) and its association with predator insects, parasitoids and ants in kale (Cruciferae) in Brazil

This study describes the fauna of predator insects, parasitoids and ants associated with aphids on kale (Brassica oleracea L. var. acephala D.C.) in organic system. The aphid was identified as Lipaphis pseudobrassicae Davis, and this is the first record of the species attacking kale in Brazil. Primary parasitism by Diaeretiella sp. and Aphidius sp. and hyperparasitism by Aphydencyrtus sp., Alloxysta sp., Pachyneuron sp. and Syrphophagus sp. were observed. Twenty species of Coccinellidae were collected, and eight of them were observed in adult and larval stages attacking the aphid: Hyperaspis (Hyperaspis) festiva Mulsant, which was the most abundant (72.5% of all predator insects obtained), Cycloneda sanguinea (L.), Eriopis connexa Germar, Coleomegilla maculata DeGeer, Hippodamia convergens Guérin, Heterodiomus sp., Scymnus (Pullus) sp.1 and Scymnus (Pullus) sp.2. Aphidophagous Syrphidae larvae collected on leaves ofkale infested by L. pseudobrassicae belong to the species Allograpta exotica (Wiedemann) and Ocyptamus gastrostactus (Wiedemann). Larvae and pupae of Syrphidae were parasitized by Pachyneuron sp., Syrphophagus sp. and Diplazon laetatorius Fabricius. Larvae of Chrysopodes sp. were observed feeding on L. pseudobrassicae. Species of ants associated with the colony of this aphid were Ectatomma quadridens Fabricius and Pheidole sp.     

Helminth parasites of the blue-footed booby on Isla Isabel, México

A survey of the helminth fauna of the blue-footed booby, Sula nebouxii, on Isla Isabel, off the Pacific coast of México, is presented. Eight parasite species were found: 4 digeneans (Galactosomum puffini , Mesostephanus microbursa, Opisthometra planicollis, and Renicola thapari), 3 nematodes (Contracaecum sp., Porrocaecum sp., and Tetrameres sp.), and 1 cestode (Tetrabothrius sp). All these species are reported for the first time in the blue-footed booby, and they represent 8 new locality records as well. Species accumulation curves suggest these 8 parasite species comprise the total helminth fauna of this population of boobies. The most frequent and abundant parasite was R. thapari, inhabiting the kidney of its host. In male boobies, a significant negative correlation was found between abundance of R. thapari and host body condition.     

云南中甸新发现的早更新世哺乳动物

描述了最近发现于横断山脉中段的一批哺乳类化石 ,具体地点位于云南迪庆州中甸县城 (香格里拉 )以南约 6km处的公路旁。这批材料包括灵长类 (Procynocephaluscf.P .wimani)、啮齿类 (Hystrixsp .)、食肉类、奇蹄类 (Equusyunnanensis)及偶蹄类 ,其中以鹿类 (Cer vavitusultimus、Eucladocerossp .、Cervus (Rusa)yunnanensis等 )和牛羊类最为丰富 ,揭示了当时一种混合的森林 -草原环境。从动物群总体面貌来看 ,这批哺乳类可与元谋人动物群相比 ,时代为更新世早期。但其中有些种类与北方早更新世类群相似 ,如真枝角鹿及羚羊等 ,表明该动物群也与北方动物群之间存在着某种生物地理上的联系。     

EXCEPTIONALLY WELL-PRESERVED MIDDLE ORDOVICIAN SPONGES FROM THE LLANDEGLEY ROCKS LAGERSTÄTTE, WALES

Abstract:  A diverse fauna of three-dimensionally preserved sponges is described from nearshore volcanogenic sandstones near Llandrindod, Mid-Wales. The fauna was preserved through early marginal silicification, in rare examples with silicification of soft tissue, and includes aspicular and spicular demosponges, hexactinellids, and a heteractinid. The fauna is largely endemic, with the following new species, genera and families erected: Onerosiconcha gregalia gen. et sp. nov., Ordinisabulo quadragintaforma gen. et sp. nov., Miritubus erinaceus gen. et sp. nov., Vadosifistula milvus gen. et sp. nov., Polycornua trescelestus gen. et sp. nov. (Pseudolanciculidae fam. nov.), P. entropus sp. nov., Palaeocallyoides improbabilis gen. et sp. nov., Reticulicymbalum tres gen. et sp. nov., Triactinella rigbyi gen. et sp. nov. (Triactinellidae, fam. nov.), Spissiparies minuta gen. nov., Brevicirrus arenaceus gen. et sp. nov., Pyritonema scopula sp. nov. (Pyritonemidae, fam. nov.) and Microastraeum tenuis gen. et sp. nov. In addition, Pseudolancicula Webby and Trotter is recorded outside Australia for the first time, although only as isolated spicules. The environment represented by this fauna has not previously yielded articulated sponges, and thus the apparent endemism may be misleading.     

Ecological parasitology of polymorphic Arctic charr, Salvelinus alpinus (L.), in Thingvallavatn, Iceland

The helminth endoparasite fauna in four Arctic charr morphs, Salvelinus alpinus (L.), small benthivorous (SB), large benthivorous (LB), planktivorous (PL) and piscivorous (PI) charr, from Thingvallavatn, Iceland consisted of: Crepidostomum farionis (Trematoda: Allocreadiidae); Diplosttomum sp. (Trematoda: Diplostomatidae); Eubothrium salvelini; Diphyllobothrium dendriticum; D. ditremum (Cestoda: Pseudophyllidae); Proteocephalus longicollis (Cestoda: Proteocepha-lidae): and Philonema oncorhynchi (Nematoda: Filariidae). The morphs exhibited distinctive patterns in prevalences and parasite burdens (mean intensity and mean relative density of parasites). SB charr had high prevalence and parasite burden of the eye fluke Diplostomum sp. and none to very light infections of the other parasite species. LB charr had relatively high prevalence and parasite burden of the intestinal fluke C. farionis , whereas infections of the remaining parasite species were light to moderate. PL and PI charr had high prevalences and worm burdens of Diphyllobothrium spp. and P. longicollis . PL charr differed from PI charr in higher worm burden off P. longicollis and lighter burden of £. salvelini . Prevalences of P. oncorhynchi were high in PL and PI charr. Association of parasite intensities and age and length offish were investigated. The different infection patterns among the morphs agree well with their partitioning in food and habitat utilization, and confirm that there is a high degree of ecological segregation between the morphs. The results demonstrate the importance of ecological factors influencing transmission efficiency of parasites to the fish host.     

A comparative study of the diet of auks killed during an oil incident in the Skagerrak in January 1981

Stomach contents were examined from guillemots Uria aalge (Pont.), Razorbills Alca torda Linnaeus and Little auks Alle alle (Linnaeus) killed by oil in the Skagerrak in January 1981. The range of prey species was small; the commonest fish found in the stomachs were Gobiusculus flavescens (Fabricius), Crystallogobius linearis (Düben), Sprattus sprattus (L.), Trisopterus minutus (L.) and Ammodytes sp. The relative importance of these fish depended on bird species and locality. Guillemots contained gadoids more frequently and sandeels less frequently than razorbills, and the composition of guillemot samples from Oslo Fjord differed from that of samples from Sweden. Invertebrate remains were uncommon in all bird species; the commonest items recorded were polychaete jaws. The frequency of occurrence of items in the diet of guillemots from Oslo Fjord was apparently influenced by the extent of oiling suffered by the birds.     

Occurrence of leeches (Hirudinea, Piscicolidae) on some marine fishes in Norway

Marine fish from several locations along the west coast of Norway were examined for leeches. Seven leech species were detected, Calliobdella nodulifera (Malm, 1863) from codfish, flatfish and a ray, Calliobdella lophii van Beneden & Hesse, 1863 from Lophius piscatorius L., Platybdella anarrhichae (Diesing, 1859) on Anarhichas lupus L., Platybdella quadrioculata Malm, 1863 on Symphodus melops (L.), Oceanobdella sp. on Zeugopterus punctatus (Bloch), Malmiana brunnea (Johansson, 1896) on Myoxocephalus scorpius (L.) and Malmiana bubali Srivastava, 1966 on Taurulus bubalis (Euphrasen). Calliobdella nodulifera infected unrelated hosts (euryxenic); the others appeared to be host specialists (oio- or stenoxenic). Details on the occurrence of Calliobdella nodulifera on Enchelyopus cimbrius (L.) during 1 year are given, which together with other observations suggest that its life cycle exceeds a year. A brief account on the morphology of “Platybdella” quadrioculata is provided, justifying its transfer to the genus Oceanobdella Caballero, 1956 as O. quadrioculata comb. nov. With the new additions, the Norwegian marine piscicolid fauna contain 12 species. At least ten additional species, known from adjoining areas, also probably occur along the Norwegian coast.     

Metazoan parasites of Alburnus chalcoides in Tödürge Lake (Zara/Sivas,Turkey)

The metazoan parasites of the Danube bleak, Alburnus chalcoides (Güldenstädt, 1772), were determined in Tödürge Lake, since the parasite fish fauna had not yet been studied in this system. A total of 106 specimens were collected from October 2004 to September 2005. Six parasite species were found: two monogeneans (Diplozoon paradoxum and Diplozoon megan), one digenean (Posthodiplostomum cuticola), one cestode (Bothriocephalus acheilognathi), one nematod (Rhabdochona sp.), and one copepod (Argulus foliaceus). About 87.7% of the Danube bleak examined were infected by at least one parasite: Rhabdochona sp. (4080 specimens), Posthodiplostomum cuticola (312 specimens) and Diplozoon megan (159 specimens) being the dominant parasites. Only 33% of the fish carried one parasitic species whilst the remainder had two (21.7%), three (17.9%) and four different species (15.1%). The frequency of infestation changed according to seasonal conditions, with a maximum 94.3% observed in spring. Occurrence, density, seasonal changes, and preferences of the parasites species for various ages and size groups of the bleak were identified, despite the limited overall sample size. D. paradoxum, D. megan, P. cuticola, B. acheilognathi, Rhabdochona sp. and A. foliaceus were determined for the first time as parasites of Danube bleak in Turkey. D. megan was also a new record for the fish parasite fauna of Turkey.     

西藏南部江孜地区早白垩世甲不拉组底栖有孔虫动物群的发现

根据最新的国际年代地层表,侏罗/白垩系界线是显生宇系一级唯一没有GSSP(全球界线层型与点位)的界线。位于特提斯喜马拉雅北亚带的江孜地区,发育了连续的侏罗/白垩系界线地层,是目前国内海相侏罗/白垩纪界线生物地层学研究最具潜在竞争力的地区之一。本文在西藏南部江孜地区甲不热北沟剖面甲不拉组底部往上3.9米处及19.3米处首次发现了胶结壳底栖有孔虫动物群,共计4属11种:Ammobaculites agglutinans,Ammobaculites sp.1,Ammobaculites sp.2,Ammobaculites sp.3,Ammobaculites sp.4,Ammobaculites sp.5,Glomospira charoides,Haplophragmoides gigas minor,Haplophragmoides sp.1,Haplophragmoides sp.2,Reophax texanus。根据该动物群重要分子的地质时限推测,甲不拉组底部往上3.9米处就已经属于白垩系地层。因此甲不拉组底部胶结壳有孔虫动物群的发现支持了将甲不拉组划归白垩系的意见。     

The effectiveness of delineating ecoregions in the Kyushu region of Japan to establish environmental indicators

Throughout Japan, numerous restoration projects and efforts to conserve the river environment are underway. However, in spite of such efforts, effective measures to conserve the river ecosystem or post-evaluation of restoration projects remain insufficient due to a lack of environmental indicators. In many European countries and the United States, a number of biological indicators have been developed and adapted. However, it appears to be difficult to directly apply these indicators to Japan, because its biota is finely classified according to its many islands and peninsulas. The ultimate goal of this study is to comprehensively evaluate indicators of aquatic biodiversity from both physical and biological aspects. We divided the Kyushu region in Japan into several ecoregions as a preliminary step to establish an indicator. We delineated the ecoregions of the Kyushu region using the fish fauna data of 21 rivers within the Kyushu region. Presence–absence (0/1) data for each fish species were used to run a two-way indicator species analysis (TWINSPAN analysis). As a result, the Kyushu region was divided into four ecoregions (A: northwest Kyushu, B1: northeast Kyushu, B2: south Kyushu, and C: Amami-Oshima Island). Each ecoregion was characterized by the following fish species: (A) Cyprinidae, in particular Acheilognathinae, is abundant; (B1) Gobiidae is abundant, while Cyprinidae such as Tanakia limbata (not confirmed in B2) are also present; (B2) Gobiidae is abundant, while Rhingobius sp. DA and Rhingobius sp. CO (not confirmed in B1) are present. These results indicate that the fish fauna of the Kyushu region is finely delineated, and that an assessment standard for biological integrity should be established, based on differences in fish fauna.     

Carboniferous (Tournaisian) fish assemblages from the Isle of Bute,Scotland: systematics and palaeoecology

We describe fish assemblages from the Carboniferous (mid‐ to late Tournaisian) Ballagan Formation at two localities, Hawk's Nib and Mill Hole, on the Isle of Bute, Scotland. Fossil material occurs in thin, locally reworked dolomitic limestone beds, interpreted as the deposits of very shallow lakes or lagoons, developed on, or adjacent to, a seasonally dry coastal plain. The mostly disarticulated fossils comprise isolated teeth, mandibles, scales, tesserae, dermal bones, lepidotrichia and vertebrae. The fauna includes rhizodonts (cf. Archichthys portlocki, cf. Strepsodus sauroides), lungfish (Sagenodus sp.), other sarcopterygians (Megalichthys sp.), one shark (Ageleodus pectinatus), climatiiform acanthodians and indeterminate actinopterygians. The Mill Hole assemblage is especially noteworthy because it includes some putative juvenile forms (Archichthys and Sagenodus). A critical review of the habitat preferences of the documented taxa suggests that most were either euryhaline or, in the case of Archichthys, probably endemic to brackish or freshwater settings. The Bute fish beds fall within a crucial evolutionary period during which many fish and other animal groups were infiltrating nonmarine environments, either passively or actively. It may be that lakes and lagoons may have functioned as protected nurseries for juveniles during this wave of colonization.     

False fairy wasps in Early Cretaceous amber from Spain (Hymenoptera: Mymarommatoidea)

Abstract: The fauna of false fairy wasps (Proctotrupomorpha: Bipetiolarida: Mymarommatoidea) occurring in Early Cretaceous (Albian) amber from north and north‐eastern Spain (Moraza, San Just, and El Soplao outcrops) is described. In total, 12 specimens have been recovered and four species recognized, all new: Alavaromma orchamum gen. nov. and sp. nov. (Alavarommatidae fam. nov.), Archaeromma hispanicum sp. nov. (Mymarommatidae), Galloromma alavaensis sp. nov., and G. turolensis sp. nov. (Gallorommatidae). The study indicates the necessity of revision and maybe fusion of both superfamilies, Mymarommatoidea and Serphitoidea, as the boundaries between them are less and less defined. However, major classificatory rearrangements must await the completion of the cladistic studies presently underway.     

Changes in the lower trophic levels as a consequence of the level of fish manipulation in the ponds

Cyprinid fish of different mature age classes (3+ -4+) and stocks (100, 300 and 500 kg/ha) were introduced into each of three experimental ponds with area of 0.3 ha (average depth ca 1.7 m) while the fourth pond was left free of fish. Bream (Abramis brama L.), white bream (Blicca bjoerkna L.) and roach (Rutilus rutilus L.) made up 75% of the total cyprinid biomass, with wild carp (Cyprinus carpio L.) as the remaining 25%. The introduced fish spawned successfully. The high (above 300 kg/ha) planktivorous and benthivorous fish stocks resulted in several qualitative and quantitative alterations of the food chain structure in our simulation pond experiments. These alterations must primarily be assigned to changes caused by both the zooplanktivory and benthivory nature of the stocked fish populations. At the higher levels of fish biomass, Secchi depth was influenced significantly by chlorophyll-a concentration. Most of the variance in suspended solids concentration could be explained by the biomass ratio of the mature benthivorous fish. There was a clear shift in algal cell size in the ponds with the higher fish stocks: ponds with more fish had larger cells later in the summer. The relative influence of young cyprinid fish on crustaceans species composition and biomass, and mature populations on benthic fauna abundance and biomass, was sufficiently greater at higher (300–500 kg/ha) fish stock rates.     

Gastrointestinal helminths of the Mexican duck, Anas platyrhynchos diazi Ridgway, from north central Mexico and southwestern United States

Twenty-five species of helminths, recovered from the gastrointestinal tracts of 129 Mexican ducks from Mexico and the United States, were all new host records. The species included: Echinoparyphium recurvatum, Echinostoma revolutum, Hypoderaeum conoideum, Notocotylus attenuatus, Prosthogonimus cuneatus, Zygocotyle lunata, Anomotaenia ciliata, Cloacotaenia megalops, Diorchis bulbodes, Diorchis sp., Drepanidotaenia lanceolata, Echinocotyle rosseteri, Fimbriaria fasciolaris, Fimbriarioides sp., Hymenolepis sp. 1, Hymenolepis sp. 2, Sobolevicanthus gracilis. Corynosoma constrictum, Polymorphus minutus, Amidostomum acutum, Echinuria sp., Epomidiostomum crami, Hystrichis varispinosus, Rusguniella arctica, and Tetrameres sp. Fimbriarioides sp. occurred predominantly in ducks from south-central Chihuahua, Mexico. The distributions for the other 24 species of the helminths were not significantly different among the four collecting areas. The helminth fauna for the 32 complete specimens and 97 intestinal tracts was distributed relatively evenly among the hosts with a calculated mean evenness of 0.77 +/- 0.15 and 0.89 +/- 0.03 respectively. The parasite fauna was more similar to those of the black duck Anas rubripes Brewster of eastern North America (53%), the mallard, Anas platyrhynchos (L.) (49%), and the mottled duck, Anas fulvigula Ridgway, from Florida (45%), than to the green-winged teal, Anas crecca (L.) (36%), the gadwall, Anas strepera (L.) (30%), and the American wigeon, Anas americana Gmelin (26%), collected in the Southwest.     

辽西狼鳍鱼(Lycoptera)属一新种

记述了辽宁阜新县大五家子镇三吉窝铺的鱼化石。该鱼具有颞孔 ,前上颌骨小 ,上颌骨大 ,辅上颌骨 1块 ,口缘有一行锥形齿 ,背鳍小于臀鳍 ,1 6根分叉尾鳍条 ,尾下骨 7块 ,尾上骨 1块 ,尾神经骨 3～ 4块。这些特征基本上是狼鳍鱼的定义特征 ,因此 ,应该属于狼鳍鱼属。阜新标本的第三眶下骨呈半圆形 ,不同于狼鳍鱼属各已知种。阜新标本的下颌长而低 ,在狼鳍鱼属中 ,只有三棵榆树狼鳍鱼和德永氏狼鳍鱼的下颌与之相似。但阜新的标本在具有 1 0根胸鳍主要鳍条、1 6根尾鳍分叉鳍条以及 1块尾上骨方面不同于三棵榆树狼鳍鱼。与德永氏狼鳍鱼相比 ,阜新标本的第三眶下骨小、半圆形、后端不伸达前鳃盖骨的前缘 ,辅上颌骨较大 ,身体较宽。根据上述阜新标本的特征 ,建立狼鳍鱼属一新种———阜新狼鳍鱼。     

Effect of several different pollens on the bio-ecological parameters of the predatory mite Typhlodromus athenas Swirski and Ragusa (Acari: Phytoseiidae)

The development, survivorship, and reproduction of the predacious mite Typhlodromus athenas Swirski and Ragusa were studied in the laboratory by rearing the predator on nine different plant pollens [almond(Prunus amygdalis Batsch), apple (Malus domestica Borkh.), apricot (Prunus armeniaca L.), cherry (Prunus avium L.), pear (Pyrus communis L.), plum (Prunus domestica L.), walnut (Juglans regia L.), olive (Olea europaea L.), Typha sp.], and pollen collected from bee hives. All experiments were conducted in environmental chambers at 20 ± 1°C, 65% RH, and a photoperiod of 16:8 (L:D) h. Survival during immature development ranged from 81.1 to 96.0%. The shortest mean developmental time from egg to adult with respect to the range of pollen species was recorded for females and males fed on almond pollen (10.76 ± 0.18 and 10.45 ± 0.21 d, respectively), while the longest was on beehive pollen (26.97 ± 0.23 and 24.00 ± 0.25 d for females and males, respectively). Female longevity varied from 51.63 ± 5.52 d (olive pollen) to 102.81 ± 6.60 d (pear pollen), while fecundity ranged from 5.33 ± 2.35 eggs per female (beehive pollen) to 26.43 ± 1.73 eggs per female (almond pollen). The diet consisting of almond pollen resulted in the highest intrinsic rate of natural increase (r(m)) (1.00 d(-1)) and pollen collected from bee hives resulted in the lowest (0.013 d(-1)). These results showed that various pollen could favor the development of T. athenas, and also support the view that alternative food resources may play an important role in the field for sustaining and increasing the predator's population.     

Helminth parasites of the oceanic horse mackerel Trachurus picturatus Bowdich 1825 (Pisces: Carangidae) from Madeira Island, Atlantic Ocean, Portugal

The helminth parasite fauna of the oceanic horse mackerel Trachurus picturatus Bowdich 1825, caught off the Madeira Islands was composed of six different taxa. Prevalence and abundance of larval Anisakis sp. (Nematoda: Anisakidae) and Nybelinia lingualis (Trypanorhyncha: Tentaculariidae), the most common parasite taxa, were 24.3%, 0.9 and 37.9%, 0.7, respectively. Bolbosoma vasculosum (Acanthocephala: Polymorphidae) and the monogeneans Heteraxinoides atlanticus (Monogenea: Heteraxinidae) and Pseudaxine trachuri (Monogenea: Gastrocotylidae) were comparatively rare. The depauperate helminth fauna of the oceanic horse mackerel at Madeira compared to other geographical regions of the north-eastern Atlantic, namely the Azores banks and the West African coast, may be attributed to the paucity of nutrients off oceanic islands and to a low density of the fish population.