141 |
Histochemistry of the developing alimentary tract of the Pacific big skate Raga binoculata GirardEvans, Robert E. January 1974 (has links)
The histochemical patterns of leucine naphthylamidase (LNAase) and alkaline phosphatase (AP) activity have been studied in the developing alimentary tracts of embryos (20 mm. - 200 mm.) of the skate Raja binoculata Girard. The enzyme(s) LNAase was found only in the spiral valve mucosae possessing elongated adult-like villi. The activity level increases with the growth of the embryo. The enzyme(s) is probably not related to differentiative events of the spiral valve but rather a manifestation of a particular stage of functional differentiation. Several possible physiological functions of the enzyme(s) are discussed. The enzyme AP had a more general distribution. It was found in many differentiating regions of the digestive tract. Activity levels which were generally high in undifferentiated mesenchymal tissue, decreased with further differentiation in some tissues. In other regions where AP remained in the adult, the enzyme accumulated with advancing differentiation. The significance of AP in the various localizations is discussed. AP isozyme patterns during alimentary tract development were studied using polyacrylamide gel electrophoresis. These data were correlated with the histochemical localization of the enzyme activity. It appears that new molecular forms of AP arise during gut differentiation. The relationship between AP and differentiation is discussed and AP is related to specific function where applicable. / Science, Faculty of / Zoology, Department of / Graduate
|
142 |
A numerical model for estimating fish productivity of large lakes /Boonyuen, Sirinimit January 1986 (has links)
No description available.
|
143 |
Taxonomy, palaeoecology and palaeobiogeography of some palaeozoic fish of Southern GondwanaEvans, F. J. (Fiona Jocelyn) 12 1900 (has links)
Thesis (PhD)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: The fossiliferous Waaipoort Formation (Witteberg Group, Cape Supergroup), Ganikobis
Formation (Dwyka Group, Karoo Supergroup) and Whitehill Formation (Ecca Group,
Karoo Supergroup) span a protracted period interrupted by a +-45Ma glacial event. This
Late Carboniferous glacial event resulted in a prolonged hiatus in sedimentation as well
as significant erosion in many southern continents of Gondwana. This study
demonstrates how the glacial episode affected faunal composition and changes in
palaeoecology in southern Gondwana across this time period. The Waaipoort shows the
highest overall faunal diversity with relatively high palaeoniscoid diversity within
Ganikobis and Whitehill Formations. This study is unique in correlating Early
Carboniferous - Early Permian fish fauna of South Africa and Namibia specifically, as
well as other parts of southern Gondwana, and includes maps of possible fish migration
routes. This study attempts to refine the body of disjointed knowledge on the taxonomy
and distribution of the fish fauna surrounding this period in southern Gondwana. Three
new Waaipoort taxa are recognised, and several reassigned. Earlier work on Late
Carboniferous fish from Southern Africa has been updated herein to incorporate recent
collections. This has allowed the recognition of up to 15 new palaeonoscoid taxa, some of
which are endemic to this region. Several new taxa are recognised within the Whitehill
Formation fish fauna and a new lectotype for Palaeoniscum. capensis is presented.
Detailed taphonomic and sedimentological studies (with 6 lithologs) of fossil localities
visited in this broad-based study verify the correlation, and impart information often lost
or ignored in pure palaeontological studies on the palaeoecology or palaeoenvironment of
the fauna. Systematic relationships discussed here also serve to strengthen the
palaeobiogeographical correlations between the Gondwanan continents. / AFRIKAANSE OPSOMMING: Die fossie1draende Waaipoort Formasie (Witteberg Groep, Kaap Supergroep), Ganikobis Formasie
(Dwyka Groep, Karoo Supergroep) en Whitehill Formasie (Ecca Groep, Karoo Supergroep) strek
oor 'n uitgebreide tydvak wat 'n periode van vergletsering van ongeveer 45 miljoen jaar insluit.
Hierdie Laat Karboon ystyd het sedimentasieprosesse lank onderbreek en beduidende erosie in
baie van die suidelike kontinente van Gondwana veroorsaak. Die huidige studie toon hoe die
vergletsering die faunistiese samestelling en veranderings in die paleo-ekologie van suidelike
Gondwana beinvloed het. In totaal toon die Waaipoort die grootste faunistiese diversiteit, terwyl 'n
relatief hoe diversiteit ook onder die Palaeoniscoidei van die Ganikobis en Whitehill Formasies
voorkom. Hierdie studie is uniek insoverre dit spesifiek data oor die Vroee Karboon - Vroee Perm
visfauna van Suid-Afrika en Namibie, asook ander gebiede van suidelike Gondwana korrelleer en
kaarte van moontlike migrasieroetes insluit. Die navorsing poog om die groot hoeveelheid
losstaande inligting oor die taksonomie en verspreiding van die visfauna in suidelike Gondwana
te verwerk en te verfyn. Drie nuwe taksa is uit die Waaipoort geidentifiseer en 'n verdere aantal is
geherklassifiseer. Vroeer navorsing oor die Laat Karboon-visse van Suider-Afrika is bygewerk in
die lig van resente versamelings. Dit het die herkenning van tot 15 nuwe taksa onder die
Palaeoniscoidei, waarvan sommige endemies aan hierdie streek is, moontlik gemaak. 'n Aantal
nuwe taksa word onder die visfauna van die Whitehill Formasie aangeteken, saam met 'n nuwe
lektotipe van Palaeoniscum capensis. Gedetailleerde tafonomiese en sedimentologiese analises
van die vindplekke wat tydens hierdie studie ondersoek is en wat 6 vertikale profiele insluit,
ondersteun hierdie korrelasie. Sodoende stel dit inligting beskikbaar wat dikwels gedurende
suiwer paleontologiese studies oor die paleo-ekologie of paleo-omgewing van die fauna verlore sou
gaan of geignoreer sou word. Die sistematiese verwantskappe wat hier bespreek word dien ook
om die paleobiogeografiese ooreenkomste tussen die Gondwana-kontinente te versterk.
|
144 |
Ichthyosarcotoxins in fishes of the Pacific Ocean: with special reference to the mechanism of actionLi, Kwan-ming., 李冠民. January 1966 (has links)
published_or_final_version / Physiology / Doctoral / Doctor of Philosophy
|
145 |
Skin defence mechanisms in fish larvaeHickey, Gabrielle Mary January 1978 (has links)
Wound healing and recovery from injury were investigated in eggs and larvae of herring (Clupea harengus L.), plaice (Pleuronectes platessa L.) and salmon (Salmo salar L.). The resistance of herring eggs to mecha.nical damage was first examined. The chorion of eggs before and just after fertilisation could be burst by loads of 4-30 g but eggs 5 h post-fertilisation could withstand over 1000 g without bursting. Resistance remained high until just before hatching when it decreased to 20-680 g. The vitelline membrane, however, showed a lower resistance at all stages. Early herring and plaice larvae were caught and eaten by medusae (Aurelia aurita, Tiaropsis multiserrata, Bougainvillea sp.), hydroids (Sarsia sp.), megalopa larvae of the prawn Nephrops norvegicus and adult mysids. Early herring larvae survived minor stings from an Aurelia ephyra, and also experimentally inflicted lesions such as superficial scratches, suction wounds and amputation of up to 2 mm of the tail in sea water. The caudal region of the primordial fin regenerated within a month when less than 1 mm was cut off. Yoll, sac and first feeding herring also survived an incision of 0.3 mm long through the body ventral to the notochord and dorsal to the gut; in starving larvae survival was poorer in the later stages of starvation. When skin was removed in larvae of all 3 species the mortality depended on the area of the lesion, thp maximum area tolerated increasing with larval size. In sea water the threshold area was 0.1-0.2 mm2 dO.r 6-8 mm long plaice, <: 0.3 mm for 10-13 mm long herring and 0.3-0.4 mm for 14-17 mm long herring. In river water the threshold was 1~2mm for 19':1l2m1m long saImon and 6.5-8 mm for 26-28 mm long salmon. The thresholds w ore about 1-3% of the total body surface area. Tolerance was increased in isosmotic salinities, the threshold area being as high as 10-14% of the body surface in 24-28 mm long salmon in 8%0. Healing of skin lesions was observed in vivo and by histology, the main response being a mass migration of epidermal cells from the periphery of the lesion. Wound areas of 0.1-7 mm closed in 4-12 h, the mean rates of cell migration being 40-110JUm/h at 10_11°C. The rate of migration was temperature dependent. The normal skin structure was restored with regeneration of a new basement membrane and dermis within 3 weeks. Older stage larvae showed an inflammatory response similar to adult fish.
|
146 |
Effects of temperature and salinity on the metabolism of red sea bream, Chrysophrys major, Temminck & Schlegel, 1842.January 1980 (has links)
by Fung Chak-yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 181-224.
|
147 |
Swimbladder morphology and buoyancy of Northeastern Pacific myctophidsButler, John Lawton 18 December 1970 (has links)
Of the common adult lanternfishes found off Oregon, two
species have fat-invested swimbladders (Stenobrachius
leucopsarus Eigenmann and Eigenmann 1890 and Stenobrachius
nannochir Gilbert 1891), two species have reduced swimbladders
(Lampanyctus ritteri Gilbert 1915 and Lampanyctus galis
Gilbert 1891), two species have gas-filled swimbladders
((Protomyctophum thomp soni (Chapman 1944)) and (Protomyctophum
crockeri (Bolin 1939)). Adult Diaphus theta Eigenrnann
and Eigenmann 1891 and adult Tarletonbeania crenularis Jordan
and Gilbert 1880 however, have either gas-filled or reduced
swimbladders. Small individuals of all the above species have
gas-filled swimbladders.
The primary buoyancy mechanism is lipids for large
S. leucopsarus, S. nannochir, L. ritteri andD. theta, is
reduction of dense material for large L. regalis, and is gas
for all juveniles and for P. thompsoni, P. crockeri and some
adult T. crenularis and D. theta. / Graduation date: 1971
|
148 |
Culverts as potential barriers to fish movementHaughey, Joanne Lee. January 2007 (has links)
Thesis (M.E.S.)--University of Delaware, 2007. / Principal faculty advisor: Clifford Keil, Dept. of Entomology & Wildlife Ecology. Includes bibliographical references.
|
149 |
Factors influencing spawning site choice by female Garibaldi, Hypsypops rubicundus (Pisces: Pomacentridae)Sikkel, Paul C. 09 May 1990 (has links)
The garibaldi, Hypsypops rubicundus, is a sexually
monochromatic pomacentrid found in rocky subtidal areas of
Southern and Baja California. During the spawning season,
males attempt to attract females to a nest of red algae
located within individually defended territories. Females
were observed to enter the nests of several males before
selecting one for spawning and were significantly more
likely to spawn in nests that contained eggs in the early
stages of development than nests with no eggs or with late
stage embryos. Among empty nests, the density of red turf
algae and the number of nesting males surrounding the nest
were inversely related to the amount of time elapsed until
a nesting male acquired the first clutch of a brood. The
percentage of long algae in the nest was positively related
to this measure. These results demonstrate active female
choice of spawning site by female garibaldi and suggest
that certain characteristics of the male-defended nest
influence this choice. / Graduation date: 1991
|
150 |
Urbanisation influences on freshwater fish distribution and remediation of migratory barriers : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Ecology in the University of Canterbury, New Zealand /Doehring, Katharina A. M. January 2009 (has links)
Thesis (M. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 118-133).
|
Page generated in 0.0266 seconds