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1.
The reproductive biology of one of the most abundant notothenioids, Patagonotothen ramsayi, was investigated between February 2003 and November 2004 on the Falkland and Patagonian Shelves (Southwest Atlantic). Male and female P. ramsayi were mature at 27.6 and 24.8 cm L T, respectively. P. ramsayi is a total spawner, with a total fecundity ranging between 24,300 and 76,700 eggs. Spawning occurs on the shelf breaks between June and August with the peak in gonado-somatic indices in June. Analysis of length frequency distributions over the year and sex ratios of mature fish during the spawning season may indicate the presence of a nesting and nest guarding behaviour in male fish, similar to other rockcods. Features of its reproductive strategy, which enabled P. ramsayi to dominate the medium-sized demersal fishes on the Patagonian shelf are discussed and compared with those of other nototheniids and cottid sculpins from the Northern Hemisphere.  相似文献   

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Caligus inopinatus n. sp. (Copepoda: Caligidae) is described and illustrated. It is parasitic on Sphyraena flavicauda (Pisces: Teleostei: Sphyraenidae) taken off Eilat, Red Sea. The influence of the host on the morphology of Caligus spp. parasitic on carangids is discussed. The author concludes that the morphological similarity among these species is an expression of their genetic relationship, rather than the effect of the host influence, although as a general proposition such influence cannot be excluded.  相似文献   

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The degree of parasitism by the parasitic copepod Sphyrion laevigatum on kingclip Genypterus blacodes in the Falkland Islands was investigated. In a sample of 719 kingclip, ranging in size from 35 to 145 cm total length, the prevalence of infection was 49%. The number of parasites per fish ranged from 0 to 24, with only 2% of the sample having more than 5 parasites. There was a significant increase in mean abundance of parasites with increasing fish age and length (P < 0.01 and P < 0.05, respectively). In addition, there was a significant difference in the prevalence in 1 of 3 geographical areas for the largest size class.  相似文献   

6.
The Falklands’ rockcod Patagonotothen ramsayi was aged successfully using whole and sectioned otoliths. Marginal increment analysis showed that one opaque and one translucent zone were laid down each year. Counting daily rings in juvenile fish and back calculating to their assumed hatch dates validated the first annulus. Readings taken from scales and otoliths showed good agreement with no significant difference between them (P>0.05). Inter- and intra-reader comparisons also showed good agreement. The maximum estimated age was found to be 14 years and the calculated von Bertalanffy growth curve L T =33.77(1−e −0.25year(t+1.07)) showed that P. ramsayi is a relatively slow growing fish that attains 5–6 cm L T in its first year and after which grows approximately 3 cm per year until 4 years. Males seemed to have a slightly lower growth rate but attained a greater maximum size than females. The formation of annuli in the otoliths of P. ramsayi seems to coincide with periods of high reproductive activity with both peaks in GSI and the prevalence of translucent margins occurring in July.  相似文献   

7.
A new species of caligid copepod, Caligus solea n. sp., is described from the common sole Solea solea (Linnaeus) caught off the north-eastern Mediterranean coast of Turkey. Both sexes of the parasite were collected from all over the upper body surface of its host. The new species belongs to the macarovi-group of species as established by Boxshall & Gurney (Bull Br Mus (Nat Hist) (Zool), 39:161–178, 1980), with which it shares the following four characters: (i) leg 4 with two-segmented exopod, distal segment carrying three apical spines but no lateral spine; (ii) distal exopodal segment of leg 1 with three plumose setae posteriorly plus four distal margin elements, spine 1 naked, spines 2 and 3 with accessory process and spine 4 about twice length of the others; (iii) females with one-segmented abdomen while males with two-segmented abdomen; (iv) male maxilliped with myxal process opposing the tip of the subchela. However, the new species differs from its congeners within the macarovi-group in the number of sensillae on each papilla on and around the postantennal process, and also in the absence of serrations along the distal margin of the maxilla. This is the twenty-eighth species of Caligus to be reported from the Mediterranean Sea.  相似文献   

8.
The ultrastructure of the mature spermatozoon of Gyliauchen sp., a parasite of the dusky rabbitfish Siganus fuscescens, was studied by transmission electron microscopy. The spermatozoon possesses two axonemes of the 9+"1" pattern of Trepaxonemata, four attachment zones, one mitochondrion, a nucleus, cortical microtubules, external ornamentation of the plasma membrane, and spine-like bodies. The main characteristics of this spermatozoon are the presence of one mitochondrion, spine-like bodies not associated with the external ornamentation, and a posterior extremity of type 3 that is characterized by the following sequence: posterior extremity of the nucleus then posterior extremity of the second axoneme. Numerous other ultrastructural features are also discussed and compared to the digenean spermatology literature. This is the first study of a member of the Gyliauchenidae and the fourth within the Lepocreadioidea. The results show that many ultrastructural characters are variable within this superfamily and could be useful for phylogeny.  相似文献   

9.
Jusheyhoea moseri (Copepoda, Chondracanthidae), a new species parasitic on deep water fishes off Hawaii, is described and illustrated. It differs from its only congener in the size and number of its trunk processes, as well as in the positions of its two pairs of legs. The latter differences necessitated redefinition of the genus Jusheyhoea. A new generic diagnosis is appended and the taxonomic value of some morphological characteristics of chondranthids is discussed.  相似文献   

10.
Lamellodiscus confusus n. sp., a diplectanid gill parasite of Sarpa salpa Linnaeus, 1758 (Sparidae) from the coast of Algeria, is described. This monogenean has been previously reported in Sarpa salpa, by various authors, under the name L. ignoratus. L. confusus n. sp. is included (among other Lamellodiscus of Mediterranean sparids) in the "ignoratus" sub-group (Amine & Euzet, 2005). L. confusus n. sp. can be distinguished from L. ignoratus by the shape and size of the haptoral ventral bar and the male copulatory organ. For comparison, illustrations of the ventral bar and the male copulatory organ of all Mediterranean species of the "ignoratus" sub-group are provided. The question of the host specificity of L. ignoratus is discussed.  相似文献   

11.
Systematic Parasitology - A new species of parasitic copepod, Caligus tunisiensis n. sp. (Caligidae), is described based on two female specimens collected from the gills of the painted comber,...  相似文献   

12.
Argentinochondria patagonensis n. gen., n. sp. (Copepoda: Chondracanthidae) is described from adult specimens recovered from the smooth kingklip Genypterus brasiliensis Reagan, 1903, from San Jorge Gulf, Patagonia, Argentina. The new genus is placed in the Chondracanthinae. Females of the new genus differ from other members of this subfamily in having 2 pairs of modified legs, a bulbose head, a long neck region, and a trunk devoid of processes. Males have usual chondracanthid form, oral appendages as in female, except a longer paragnath, fewer teeth on maxilla, and 2 pairs of reduced legs.  相似文献   

13.
Bomolochus peruensis n. sp., a parasite of the sciaenid fishes Menticirrhus ophicephalus and Sciaena deliciosa from the central Peruvian coast, is described and illustrated. The new taxon differs from all other Bomolochus species in a combination of characteristics of leg 2, leg 4 and leg 6 and by the presence of spinules on the ventral surface of the last abdominal segment only. This is the first record of Bomolochus from South America.  相似文献   

14.
Summary Clavella applicata n. sp. and C. caudata n. sp. are described and illustrated. Both species are parasitic on the fins (the latter also on the inner surface of the operculum) of Anisotremus scapularis (Tschudi), an inshore teleost fish from Antofagasta, Chile. Both new species can be distinguished from their congeners, and from each other, by various details of their appendages. C. caudata is unique in possessing modified uropods. The dorsal position of these appendages suggest that the Clavella-branch of Lernaeopodidae is related more closely to the Charopinus-branch than to Brachiella-branch of the family. C. parva Wilson, 1912, is recorded for the first time from Chilean waters, where it was found on the caudal fin of Mugiloides chilensis (Molina). ac]19840504  相似文献   

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Thamnocephalus cerebrinoxius n. g., n. sp. is a sphyriid copepod found in the nasal capsules of a small enzootic west African shark, Leptocharias smithii (Leptochariidae), caught off the coast of Senegal. The most characteristic feature of this copepod is its holdfast of numerous, profusely branching dendrites that penetrate the olfactory lobe of the host's brain. This type of host-parasite relationship is unique among all known parasitic copepods.  相似文献   

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A new genus and species of myxozoan parasite,Renispora simae, is described from the gall-bladder of the nototheniid fishPatagonotothen sima (Richardson). Four of 12 fish caught in Stanley harbour in the Falkland Islands in May, 1993 were infected. The new genus is placed in the family Alatosporidae and differs from other genera in this family by the shape of the spore body and the shape and site of adhesion of the membranous extensions to the spore valves. To accommodate the new genus, we propose an amendment to the definition of the family Alatosporidae to include forms with reniform spores.Myxidium baueri Kovaleva & Gaevskaya, 1982 is reported fromP. sima for the first time. It was found in the gall-bladder of one of the same 12 fish caught in Stanley harbour.  相似文献   

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Albionella fabricii n. sp. is described from the gills of the black dogfish Centroscyllium fabricii caught off the west coast of Newfoundland. Morphological differences are found in all the female and male appendages between Albionella fabricii n. sp. and A. centroscyllii, another species occurring concurrently on the same host. Female A. fabricii n. sp. can easily be distinguished from its four congeners by the length and structure of the second maxillae and the length of the uropods. A comparison between Albionella fabricii n. sp. and identifiable females of the genus Lernaeopoda is necessary, since both genera differ mainly in the morphology of the male. Two specific characteristics, the number of secondary denticles on the claw of the maxilliped and the number of setae on the exopod of the first maxilla, distinguish females of Albionella from those of Lernaeopoda.  相似文献   

19.
Systematic Parasitology - Thirteen species of sea lice (family Caligidae) are reported from a range of elasmobranch and actinopterygian fishes caught off South Africa or obtained from public...  相似文献   

20.
Summary One new genus and two new species of the Lernaeopodidae (Copepoda: Siphonostomatoida), parasitic onTriakis maculata off the coast of Chile, are described and illustrated. The new genus,Pseudolernaeopoda, parasitizes the cloaca of its host. Its type-species,P. caudocapta, can be distinguished fromLernaeopoda by the absence of modified uropods. A new species ofLernaeopoda, L. tenuis, was found on the gills of the same host. In absence of the male, the generic affinities of this species must be considered only tentative. ac]19850409  相似文献   

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