Spelling suggestions: "subject:"ophiostomatoid.""
1 |
A contribution to the biology of caligoid copepods parasitic on acanthurid fishes of the Hawaiian IslandsLewis, Alan Graham January 1961 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii, 1961. / Bibliography: leaves [453]-471. / xii, 471 l illus. (part mounted) diagrs., tables
|
2 |
A taxonomic study of selected representatives of siphonostomatoida (copepoda) from ostechthyes in coastal waters off Southern AfricaSebone, Makwena Melita January 2023 (has links)
Thesis (M.Sc. (Zoology)) -- University of Limpopo , 2023 / Currently Copepoda consists of 14 600 species of which 2 275 species are members
of the Siphonostomatoida. Siphonostomatoida consists of 40 families, with 17 families
symbiotic on fish. Sphyriidae has 44 accepted species in eight reported genera, of
which four genera infect teleosts and the remaining four infect elasmobranchs. Adult
females undergo transformation through loss of locomotory appendages to suit their
mesoparasitic lifestyle and develop outgrowths on the cephalothorax or neck for
attachment to the host. To date, only 176 marine siphonostomatoid species have been
reported from South African waters, with only nine sphyriid species.
Sphyriids previously collected from marine bony fish off the east, south and west
coasts of southern Africa and preserved in 70% ethanol were studied. Specimens
were examined with stereo- and compound microscopes and identified using
published literature. Selected specimens were stained in lactic acid with added lignin
pink, appendages were dissected and illustrated with the aid of a drawing tube.
Selected specimens were also studied through scanning electron microscopy.
The examined specimens were identified as species of Sphyrion and Lophoura. Re descriptions were done for all valid Sphyrion species females (S. laevigatum, S. lumpi
and S. quadricornis) and new descriptions for the males of S. laevigatum and S.
quadricornis. Post-metamorphosis females of Sphyrion species can be differentiated
by the shape of cephalothorax, length of the neck in relation to the length of the trunk
and the length of posterior processes in relation to the trunk length, while males are
mostly very similar. New information is provided regarding the appendages of S.
laevigatum and S. quadricornis. The appendages of the three species bear close
resemblance to one another. Additionally, an identification key for the post metamorphosis females of Sphyrion species is provided.
Re-descriptions were done for five female Lophoura species (L. caparti, L. cornuta, L.
cf edwardsi, L. tetraloba and Lophoura sp.) and a new description of the male of L.
tetraloba. Differences between young and post-metamorphosis females of L. cf
edwardsi and L. tetraloba were observed in the width of the holdfast organ processes
and the length of porous peduncle and stalks of the posterior processes which appear
to grow with age. The difference between the young and adult male of L. tetraloba lies
in the lengths of the cephalothorax in relation to the trunk length and segmentation
visible on the trunk of the young male but not adult male. The post-metamorphosis
females of Lophoura species can be differentiated by the shape and number of
processes on the holdfast organ, in combination with the cephalothorax length in
relation to the neck length, neck length in relation to the trunk length, shape of the
trunk, and the length and structure of the posterior processes. An identification key
was drawn up for all species of the Lophoura post-metamorphosis females.
An attempt was made to provide the COI barcodes for all the species of Sphyrion and
five species of Lophoura. These would have confirmed the species identification of
morphologically variable species e.g. S. laevigatum and S. lumpi and also provide an
estimation of the interspecific divergence amongst the different species. Additionally,
it would have assisted in distinguishing between L. tetraloba and L. cf edwardsi and
provided an estimation of the amount of sequence divergence between the two
genera. Unfortunately sequencing of apparently successfully amplified products was
unsuccessful probably due to low DNA quality which possibly degraded due to
collection methods used for the fish hosts and parasites and prolonged preservation
of specimens.
This study provides new host records i.e. Coelorinchus simorhynchus, Coelorinchus
trunovi and Saurida undosquamis for Sphyrion quadricornis off South Africa which is
also a new geographical record. Allocyttus verrucosus, Coelorinchus simorhynchus,
Coelorinchus trunovi, Mesovagus antipodum and Ventrifossa nasuta are also new
host records for S. lumpi. Additionally, Epigonus denticulatus and Bassanago
albescens are new host records for Lophoura caparti and L. cornuta respectively off
South Africa, which is a new geographical record for both species. Furthermore,
Coelorinchus fasciatus and Lucigadus ori are new host records for Lophoura tetraloba
and L. cf edwardsi off South Africa, which is also a new geographic record for both
species. Thus, the results of the study improve the current knowledge of the marine
siphonostomatoid biodiversity off South Africa as well as their distribution and infected
hosts. / National Research Foundation (NRF)
|
3 |
A systematic study of selected kroyeria species from the South African coastMokumo, Peter Jabu January 2014 (has links)
Thesis (MSc. (Zoology)) -- University of Limpopo, 2014 / One of the 11 families of the siphonostomatoids found parasitic on elasmobranchs is the Kroyeriidae which has three accepted genera namely Kroyeria, Kroeyerina and Prokroyeria. Parasites from this family are found living on the gills (Kroyeria spp. and Prokroyeria sp.) or in the nasal fossae (Kroeyerina spp.) of Chondrichthyes. There are currently 21 nominal species in the genus Kroyeria.
Kroyeria specimens were collected from the gill filaments of their elasmobranch hosts which were caught: (1) in the nets of the KwaZulu-Natal Sharks Board (KZNSB) installed along the east coast of South Africa, (2) by commercial fishermen off the west coast at Gansbaai as well as (3) during the demersal trawls of Department of Agriculture, Forestry and Fishery (DAFF) off the south and west coasts. Collected specimens were fixed and preserved in 70% ethanol. Morphological features were drawn where necessary to illustrate differences from previously described features. Host-parasite relationships of the different species were determined by calculating prevalence, mean abundance and mean intensity on their hosts as well as estimating the pattern of dispersion by calculating the coefficient of dispersion. DNA was extracted from selected identified samples. A partial fragment of the COI gene was amplified via PCR using the forward and reverse universal primers LCO 1490 and HCO 2198, or those with additional M13 tails, LCO 1490_t1 and HCO 2198_t1. Additionally, the complete 18S rDNA gene of some species was amplified using the forward and reverse primers as follows: 18Sf and 1282r for the first fragment, 554f and 614r for the second fragment and 1150f and 18sr for the third fragment. Phylogenetic relationships among different Kroyeria species were estimated by employing neighbor joining (NJ), parsimony (MP) and maximum likelihood (ML) in PAUP*. The use of real-time PCR and melt curve analysis to distinguish among different Kroyeria species based on their different melt temperatures of a part of the COI gene was also attempted.
Eleven Kroyeria species were found on the gill filaments of elasmobranchs belonging to the families Carcharhinidae, Sphyrnidae and Triakidae off the coasts of South Africa. These include K. carchariaeglauci from C. leucas; K. decepta from C. obscurus; K. deetsi from C. brevipinna; K. dispar from G. cuvier; K. elongata from R. acutus; K. lineata from M. palumbes; K. longicauda from C. limbatus; K. papillipes
viii
from G. cuvier; K. procerobscena from both C. leucas and C. amboinensis; K. sphyrnae from both Sphyna lewini and S. zygaena and a new Kroyeria sp. from G. galeus. This is the first record of K. lineata from the south coast of South Africa and is also as a new host record for Mustelus palumbes. Three Kroyeria species have previously been reported from G. galeus, namely K. brasiliense, K. lineata and K. rhophemophaga. The new Kroyeria sp. is most similar to K. rhophemophaga which in turn shares morphological features with K. triakos. However, the Kroyeria sp. can be distinguished from both K. rhophemophaga and K. triakos in the armature of the legs.
Most Kroyeria species are relatively host specific, infecting a single host or related group of host species. During this study two species, K. dispar and K. papillipes were collected from G. cuvier, while K. procerobscena and K. sphyrnae were each collected from two host species. Kroyeria sp. and K. dispar displayed very high prevalence values, 95.7% and 94.1% respectively, in contrast to the other Kroyeria species which have lower values (6.3–68.6%). Additionally, when compared to other siphonostomatoid species such as Nemesis lamna, Kroyeria species have relatively low prevalence values. Kroyeria species generally have low parasite loads (between 4 and 33 copepods per infected host), except for K. dispar which has a high mean intensity of 74 copepods per infected host. The mean abundance of Kroyeria species is also generally low (between 0 and 23 per examined host), with K. dispar (69 individuals per examined host) being an exception. Furthermore Kroyeria species generally display an aggregative pattern of distribution which is common in most copepod species indicating that individuals have social interactions.
A preliminary estimation of the phylogenetic relationships among seven Kroyeria species revealed topologies with unresolved polytomies. The 18S rDNA gene did not make any significant changes on the topology, except that it produced very minimal resolution in one of the groupings. Therefore, COI is found to be a gene of choice that can be used in estimating molecular phylogenetics and population genetics of siphonostomatoids as it provides useful sequence divergence within individuals of the same species as well as among congeneric species due to its fast evolving rate. However, in this study, single species did not form monophyletic groupings.
ix
The 18S rDNA gene is found to be very conservative, providing no sequence divergence within individuals of the same species and very little divergence among conspecifics due to its low mutation rate and is therefore more useful at genus and family levels.
With polytomies in the estimated phylogenetic relationships, haplotype networks were used to compare the distribution of different haplotypes among the different species. Haplotype sharing did occur between species e.g. for COI, H1 is shared by K. lineata, Kroyeria sp. and K. sphyrnae. This haplotype sharing by different species is unexpected and could be due to specimen misidentification before DNA extraction. Specimen misidentification is common for Kroyeria species because some of them are not easy to identify. The haplotype network results confirmed the relationships shown by the phylogenetic trees, dividing Kroyeria species into three different groupings.
Real-time PCR and melt curve analysis have the potential to distinguish among Kroyeria species. However, the quality of the extracted DNA is an important factor in producing successful amplifications and determining the Tm. Therefore it is necessary to ensure that the extracted DNA has the ideal concentration of 50 ng/μl and is free of Taq polymerase inhibitors such as phenol, RNA and guanine residuals from the extraction process.
|
4 |
Taxonomia de Asterocheridae (Copepoda : Siphonostomatoida) associado a esponjas do litoral brasileiroSilva , Rodrigo Johnsson Tavares da January 1997 (has links)
Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-06-15T17:32:36Z
No. of bitstreams: 1
273728.pdf: 13102209 bytes, checksum: 521bb732d2ce883a31275f4835400293 (MD5) / Made available in DSpace on 2018-06-15T17:32:36Z (GMT). No. of bitstreams: 1
273728.pdf: 13102209 bytes, checksum: 521bb732d2ce883a31275f4835400293 (MD5)
Previous issue date: 1997 / CAPES / FUJB / O litoral brasileiro possui a fauna de Siphonostomatoida parasita de peixes
relativamente bem conhecida contudo não se tem registros de espécies de
Siphonostomatoida associados de invertebrados. Deste modo foram realizadas coletas em
três diferentes pontos do litoral brasileiro, Ilhas Cagarras, Rio de Janeiro (RJ), Recife de
Viçosa, Nova Viçosa (BA) e Porto de Galinhas (PE), para o levantamento taxonômico de
Siphonostomatoida.
Nessas coletas foram analisadas as espécies de Siphonostomatoida Asterocheridae
associadas à Porifera.
Nove espécies novas são descritas, sendo seis do gênero Asterocheres (A.
abrolhensis n. sp., A. crenulatus n. sp., A. Junatus n. sp., A. paraboecki n. sp., A.
spinopaulus n. sp. e A. tetrasetosus n. sp.), uma de Asteropontoides (A. elephantinus n.
sp.), uma de Cletopontius ( C. titanus n. sp.) e uma de Monocheres (M. cagarrensis n. sp.).
Foi descrito, pela primeira vez, um macho do gênero Cletopontius. Além dessas espécies
novas, um novo gênero (Kolomyzon n. gen.) de Asterocheridae é descrito para a espécie
Kolomyzon angustus n. gen. n. sp.
Chaves para a identificação dos gêneros de Asterocheridae e para as espécies de
todos os gêneros estudados são apresentadas.
O gênero Asterocheres que possui uma distribuição mundial é pela primeira vez
registrado para o Atlântico Sul Ocidental. Asteropontoides, Cletopontius e Monocheres
cujas espécies eram apenas conhecidas para o Oceano Índico também foram registradas
para o Oceano Atlântico. / The Brazilian coast has the Siphonostomatoid species that parazitise fishes relatively
well known, however there are no records of the Siphonostomatoid species that live
associated with invertebrates. Thus, sampling was clone in three diferent areas of the
Brazilian coast: Cagarras Islands, Rio de Janeiro (RJ) ; Viçosa Reefs, Nova Viçosa (BA) and
Porto de Galinhas (PE) , to study these Siphonostomatoids.
ln these samples the Asterocheridae species associated with Porifera were analyzed.
Nine new species are described, six of them belonging to the genus Asterocheres
(A. abrolhensis n. sp. , A. crenulatus n. sp., A. lunatus n. sp., A. paraboecki n. sp., A.
spinopaulus n. sp. and A. tetrasetosus n. sp.) , one to Asteropontoides (A. elephantinus n.
sp. ) , one to Cletopontius ( C. titanus n. sp.) and, one to Monocheres (M cagarrensis n. sp. ) .
For the first time a male from the genus Cletopontius is described. Besides these new
species a new genus (Kolomyzon n. gen.) of Asterocheridae is described to the species
Kolomyzon angustus n. gen. n. sp.
Keys for the genera of Asterocheridae and for the species of the studied genera are
presented.
The genus Asterocheres has a worldwide distribution, but for the first time, it is
recorded for the South western Atlantic. Asteropontoides, Cletopontius and Monocheres
whose species were only known from the lndian Ocean were also first recorded for the
Atlantic Ocean.
|
5 |
Studies on the biology and ecology of the free swimming larval stages of Lepeophtheirus Salmonis (Kroyer, 1838) and Caligus Elongatus Nordmann, 1832 (Copepoda: Caligidae)Gravil, Helen Ruth January 1996 (has links)
The study investigated biological and ecological parameters controlling and influencing the production and distribution of the free-swimming larval stages of Lepeophtheirus salmonis (Kroyer, 1838), and to a lesser extent Caligus elongatus Nordmann 1832, in the natural environment The reproductive output of L. salmonis was influenced by seasonal effects. The number of eggs produced per brood showed an inverse relationship with increasing temperature. The number of eggs per brood was also influenced by adult female body size (cephalothorax length), which in itself exhibited an inverse relationship with increasing temperature. Photoperiod had no significant effect upon the number of eggs produced or on adult female size. Mean egg size of L. salmonis varied significantly over the year; larger eggs were produced during the summer months and smaller eggs over the winter. However, factors controlling the size of the eggs were not elucidated. The proportion of viable eggs per L. salmonis ovisac remained constant throughout the year. Large variations in egg number per egg string were found in both L. salmonis and C elongatus populations sampled at one point in time. These were attributed in part to phenotypic variation in adult female size and also the number of broods individual females had produced. Egg viability was not correlated with brood size, but mean egg size was related to the number of eggs per brood. Experimental studies indicated that hatching and development of L. salmonis was highly variable. The percentage of eggs hatched and the time period over which hatching occurred varied markedly, even when held under constant and optimal environmental conditions. Temperature did not affect hatching success or viability of the nauplius I stage, although at higher temperatures the period over which hatching occurred was reduced. Low and medium salinities caused a significant decrease in both hatching success and nauplius viability. Photoperiod had no effect on initiation of hatching. Hatching occurred in a manner similar to that observed in free-living copepods. The nauplii were enclosed by two egg membranes, the outer one bursting within the ovisac, the inner one after the ovisac membrane has split. Swelling of the egg and its subsequent hatching was attributed to osmotic effects, with water being taken up from the external environment. Development was also highly dependent upon both temperature and salinity. At 5'C, nauplius 11 stages failed to enter the moult to the copepodid stage. At 7.5'C, although moulting was initiated, in a large proportion of cases it was not successfully completed. At I O'C, development to the copepodid stage was successful. Nauplii only developed successfully to the copepodid stage at salinities of 25%o or greater. Copepodids raised under optimal conditions then exposed to a range of salinities had a greater salinity tolerance than nauplii. Biochemical analysis of the eggs of L. salmonis revealed that lipids constituted a large proportion of their dry weight. Naupliar stages contained a discrete area containing lipid which decreased in size over time, suggesting that the free-swimming larval stages utilised this as an energy reserve. Rate of depletion was faster in nauplii held at higher temperatures. Longevity, activity and infectivity of the infective stage decreased with age. However, both spontaneous and stimulus dependent activity ceased many hours before death and both activity and longevity were affected by temperature. Infectivity of I day old L. salmonis copepodids was higher than 7 day old larvae, and was considered to be related to the size of the energy reserves. The settlement and distribution pattern of copepodids did not change with age of copepodid, the majority being recorded from the fins. All three L. salmonis free-swimming larval stages demonstrated a "hop and sink" swimming pattern. The velocity and duration of both passive sinking and active swimming was recorded for both nauplii and copepodids. Although greater periods of time were spent passively sinking, the speeds obtained during both upward spontaneous and stimulated swimming meant that a net upward movement of larvae in the water column occurred. At higher temperatures spontaneous swimming activity increased, whilst low salinities caused a cessation of such ability. L. salmonis larvae were positively phototactic and negatively geotactic. As well as their positive responses to light intensity, the nauplius 11 and copepodid stages reacted positively to blue-green spectral wavelengths. Moulting times were relatively short, although the larvae were not able to swim during such periods. No relationship was found between the level of lipid reserves and the overall buoyancy of the larvae. Naupliar stages of both L. salmonis and C. elongalus were obtained from the water column as a result of a plankton sampling programme at a commercial Atlantic salmon farm. No copepodid stages of either species were found. There was no difference in the vertical distribution of the two L. salmonis naupliar stages. Live larvae tended to aggregate between 0 and 5m in depth, with no diurnal vertical migration. Dead nauplii, and those with low lipid reserves, were found deeper in the water column. Naupliar stages, and in particular the first larval stage, were concentrated in number within cages indicating that the cages have a retentive characteristic. A novel control method in the form of a commercially available light lure was tested. Though increasing the numbers of free-living copepods captured, it had no effect on the numbers of L. salmonis naupliar or copepodid stages obtained in plankton samples. The present study has therefore provided valuable data concerning the biology and ecology of the free-swimming larval stages of sea lice, in what was a comparatively poorly understood area.
|
Page generated in 0.038 seconds