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

No description available.

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.

published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

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.

by Fung Chak-yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 181-224.

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

Thesis (M.E.S.)--University of Delaware, 2007. / Principal faculty advisor: Clifford Keil, Dept. of Entomology & Wildlife Ecology. Includes bibliographical references.

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

Thesis (M. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 118-133).