The Dissertations Sticky

[Jools]

This sticky is for the posting dissertation research that may be of interest to forum users. Please note that dissertations are not considered valid publications by the International Code of Zoological Nomenclature, so any nomenclatural acts in dissertations are not considered valid.

[Shane]

Amanda Stokes' Thesis
"Tests of Adaptive Coloration Hypotheses for Madtom Catfises"

http://www.uno.edu/theses/submitted/etd ... amanda.pdf

-Shane

[Silurus]

Cook-Hildreth, SL, 2009. Exotic Armored Catfishes in Texas: Reproductive Biology, and Effects of Foraging on Egg Survival of Native Fishes (Etheostoma fonticola, Endangered and Dionda diaboli, Threatened). Theses and Dissertations-Biology. Paper 18.

[racoll]

Please tell me these were actually Hypostomus...



P.S. There doesn't seem to be a "head in hand" smiley.

[apistomaster]

I read the thesis and wondered the same thing. I have never heard of Hypostomus spp in Texas.
But I noticed several TFH publications were referenced which was a red flag to me that someone didn't really do all their home work.

Thesis Summary:
Placed adhesive eggs on substrate in with large, starved Plecos in confinement and found that the catfish ate 2/3 of the eggs.

[Dave Rinaldo]

I always assumed the plecos were Pterygoplichthys spp.

http://southwestinvasivespecies.org/Suc ... xasHO1.pdf

[Silurus]

P.S. There doesn't seem to be a "head in hand" smiley.

I think it's about time we had a facepalm smiley.

[racoll]

[Mike_Noren]

It's just a Master of Science thesis not a Doctor of Philosophy thesis. The facepalming should be directed towards whomever it was who tutored the student.

[sidguppy]

perfect proof of the fact that a degree doesn't keep people from being dumb as a post and it also is perfect proof that next to hydrogen the most common element in the universe is stupidity.
I'm not so sure about the hydrogen.


this looks like genuine Homer Simpson science to me:

Thesis Summary:
Placed adhesive eggs on substrate in with large, starved Plecos in confinement and found that the catfish ate 2/3 of the eggs.

conclusion: duh!

[Silurus]

If you are interested in Nathan Lujan's PhD dissertation on jaw morpho-functional diversity, trophic ecology, and historical biogeography of the Neotropical suckermouth armored catfishes (Siluriformes, Loricariidae), it can be downloaded here.

Be forewarned, it's a large (56MB) download.

[DP German]

I've read it. It is a great piece of work, and, because the stable isotope data jive with mine, I think it is even better. Plus, Nathan is just a cool guy.
Cheers,
Donovan

[bronzefry]

Never a small thing to get a phd. Congrats, Nathan!
Amanda

[Silurus]

Thomas, MR, 2011. Systematic revision of the South American armored catfish genus Loricaria (Siluriformes: Loricariidae). Unpublished PhD dissertation, Southern Illinois University at Carbondale.

Abstract

The genus Loricaria Linnaeus of the family Loricariidae is diagnosed as a monophyletic group based on two uniquely derived synapomorphies: lower lip surfaces covered with filiform papillae and absence of buccal papillae surrounding the dentary teeth. Loricaria are small to moderate-sized catfishes widely distributed throughout most of the major river drainages of cis-Andean South America, including the Amazon, Orinoco, Paraguay, Paraná, and smaller coastal rivers draining the Guyana and Brazilian Shields. Based on multivariate analyses of morphometric and meristic data in combination with qualitative assessment of external morphological characters, 15 nominal species are accepted as valid, with an additional nine described as new. Among the nominal species, L. lentiginosa is synonymized with L. prolixa. Loricaria carinata is resurrected from synonymy with L. cataphracta and L. simillima is treated as a junior synonym of L. carinata. Formal diagnoses, descriptions, and a key to all 24 species are provided. Phylogenetic analyses of Loricaria and related taxa (Spatuloricaria, Crossoloricaria, Planiloricaria, Brochiloricaria, Paraloricaria, and Ricola) based on a combined data set of 32 gap-coded quantitative (morphometric and meristic) characters and 24 qualitative characters derived from external morphology resulted in fully resolved, but poorly supported phylogenies under equal weights and implied weighting criteria. Implied weights analyses using a concavity constant (K) of 24-49 recovered Loricaria as a monophyletic group with L. piracicabae as basal and sister to six terminal clades containing all other species. Species originally described as Loricaria, but subsequently transferred to Brochiloricaria, Paraloricaria, and Ricola, were recovered as paraphyletic in each analysis and should be treated as congeneric with Loricaria. Distributions of Loricaria exhibit patterns of endemism similar to those documented for other groups of Neotropical fishes. Species diversity is highest in the Amazon basin (13 species, including 10 endemics), followed by the Paraguay region (5 species, including 4 endemics), Guianas region (5 species, including 2 endemics), Orinoco basin (3 species, including 2 endemics), and a single species occurring in both the São Francisco basin and drainages of Northeastern Brazil. Loricaria is apparently absent from coastal Atlantic drainages south of the São Francisco basin. Such shared patterns of endemism provide some insight into past geomorphological processes that have influenced diversification in Loricaria and serves as a foundation for further tests of biogeographic hypotheses based on phylogenetic and geological evidence.

[Silurus]

(Hardly) More info here.

Since this is an unpublished dissertation, the taxonomic decisions are not considered validly published.

[Silurus]

Jeremy Wright has successfully defended his PhD dissertation [The evolutionary ecology of venomous catfishes, with a focus on members of the North American family Ictaluridae (Teleostei: Siluriformes)], which can be downloaded here.

[racoll]

Well done Jeremy (if you're still a registered member here)!

[bekateen]

Peart, CR; (2015) Detecting a signature of adaptive radiation: diversification in Lake Tanganyika catfishes. Doctoral thesis, UCL (University College London).

ABSTRACT
This thesis compares two independent radiations of catfish in Lake Tanganyika, Claroteine and Synodontis catfishes, to investigate generalities in patterns and processes of diversification between radiations in an ancient “island-like” environment. The introductory chapter places this work in a theoretical context and explores previous research on taxa from Lake Tanganyika. Chapter two provides the first molecular phylogeny of species in the sub-family Claroteinae from Lake Tanganyika, including additional putative species of the genus Phyllonemus. This phylogeny is fossil calibrated to assess when diversification occurred and molecular species delimitation is also performed. Chapter three investigates geographic structure in one species from each radiation, Lophiobagrus cyclurus (from the Claroteine radiation) and Synodontis multipunctatus. Each species was sampled from multiple localities along the length of Lake Tanganyika and their DNA sequenced using restriction site associated (RAD) sequencing to produce large genomic datasets. These datasets allow the comparison of geographic patterns between taxa and, in the Lophiobagrus dataset (which also includes the closely related species L. aquilus), an investigation into the extent of introgression. Chapter four investigates niche partitioning and morphological diversification in both the claroteine and Synodontis radiations. These analyses are conducted using a single dated molecular phylogeny containing both of the radiations allowing explicit comparisons. Eco-morphological divergence is assessed using both morphological measurements thought to be ecologically relevant (e.g., size of the eye) and stable isotope ratios of both nitrogen and carbon as a proxy for niche space. While the first three chapters investigate generalities in the patterns and drivers of diversification by comparing two independent radiations in the same “island-like” environment, Chapter fives takes a different approach by placing one of the Lake Tanganyika radiations, Synodontis, in its broader phylogenetic context. In this chapter morphological diversification is investigated in the largely riverine continental radiation of Synodontis found throughout sub-Saharan Africa.

This dissertation is not yet available freely.

[Richard B]

March 2017

[bekateen]

Stéphanie L. Lefebvre. 2014. Is Diet Correlated with Feeding Morphology in Neotropical Suckermouth Armoured Catfishes (Siluriformes: Loricariidae)? Masters Thesis, University of Toronto

ABSTRACT
The suckermouth armoured catfishes (Siluriformes: Loricariidae) are a diverse group of predominantly detritivorous fishes inhabiting rivers of South and Central America. Their distinct jaws are specialized for scraping a wide range of substrate. Though it is hypothesized that specialization of loricariid feeding morphology may have played a role in their diversification, little is known about the ecological and evolutionary processes involved. The present study quantifies variation in jaw functional traits and body morphology in a phylogenetic context. Morphological variation was compared to species’ relative position in assemblage isotope space (for both δ13C and δ15N) to test for correlations between diet and feeding morphology. Results show that although jaw functional traits are decoupled from body morphology, both are correlated with δ13C values. Partitioning of terrestrial and aquatic resources can be explained by both jaw functional traits and body morphology, however further partitioning of diet is only attributed to the former.

[bekateen]

Padmi, Ni Komang Ayu Oka. 2015. Ichthyoacanthotoxins pada Beberapa Jenis Catfish: Clarias gariepinus (Clariidae), Pangasius hypophthalmus (Pangasidae), Plotosus canius (Plotosidae). Thesis, IPB-Bogor Agricultural University.

ABSTRACT
Ichthyoacanthotoxins are toxins released through the pectoral fins (horn) by venomous fish. Order Siluroidea like

CLARIAS GARIEPINUS

,

PANGASIUS HYPOPHTHALMUS

, and

PLOTOSUS CANIUS

generally have pectoral fins as a defense mechanism. The research was conducted from February 2014 through September 2014 to determine anatomical structure of the venom gland and the chemical composition (acanthotoxins) present in the pectoral and dorsal spine. The results of histological analysis showed that the anatomical structure pectoral and dorsal spine consists of pieces of muscle, adipose layer, blood vessels, and there is a venom gland at CLARIAS GARIEPINUS with a long shaft, which is 1612.48 μm. The results showed that the proximate analysis, protein content of PLOTOSUS CANIUS is higher than the protein content of CLARIAS GARIEPINUS and PANGASIUS HYPOPHTHALMUS, while the fat content of CLARIAS GARIEPINUS higher than the fat content of PANGASIUS HYPOPHTHALMUS and PLOTOSUS CANIUS.

[Silurus]

Cohen, MS, 2015. Host-parasite interactions of the African cuckoo catfish (Synodontis multipunctatus). PhD dissertation, University of Colorado at Boulder, 117 pp.

Abstract

Obligate brood parasitism (completely relying upon a host for successful breeding) has been studied in insects and birds, with a considerable amount of research concentrating on birds such as cuckoos and cowbirds. The Lake Tanganyikan cuckoo catfish (Synodontis multipunctatus Siluriformes: Mochokidae) is the only known non-avian obligate brood parasite among vertebrates, and it uses female mouthbrooding cichlids (Perciformes: Cichlidae) as hosts. Although the basic breeding mechanism of the cichlid-cuckoo catfish system has been well documented through a series of observational studies, there have been few manipulative experiments concentrating on host-parasite interactions. The goal of my dissertation work was to examine this parasitic relationship from the perspectives of both the host and the parasite in the context of ecology and coevolution. Specifically, I was interested in how hosts avoid or mitigate parasitism, as well as features of the parasite that allow for successful parasitism. First, I assessed parasitism frequencies among cichlid hosts and discovered that sympatric Lake Tanganyikan hosts were parasitized significantly less than allopatric hosts from other lakes in laboratory conditions, possibly explained by subtle differences in mating ritual and oviposition, or increased aggression by sympatric hosts. Next, I compared unparasitized and parasitized broods to show that the cuckoo catfish indiscriminately parasitize all sizes of host, followed by complete elimination of host progeny and subsequent cannibalism while being brooded in the host mouth. Finally, using live fish and video playback techniques, I found that visual cues play an important role in breeding synchrony between the cuckoo catfish and cichlid hosts. Together, my dissertation provides the groundwork for using this unique cichlid-cuckoo catfish system as a model for studying brood parasitism in controlled laboratory conditions, where questions regarding parasitism dynamics in the context of both ecology and coevolution can be addressed.

[Silurus]

Calegari, BB, 2015. Sistemática filogenética dos bagres Auchenipteridae (Ostariophysi: Siluriformes): uma abordagem combinando dados morfológicos e moleculares. PhD dissertation, Pontifícia Universidade Católica do Rio Grande do Sul.

Abstract

The Auchenipteridae have an extensive and confusing taxonomic and phylogenetic history. Several studies developed since 1766 involving descriptions of species generated controversial results about the composition of the family and their interrelationships. The weakness of the systematic knowledge and diversity of the family hinders the understanding about the evolutionary history since the informative potential of morphology, molecules and biogeography was not yet fully explored. A comprehensive and densely sampled phylogenetic study of the species relationships of the Auchenipteridae, a Neotropical family of inseminating catfishes, is here documented based on combined datasets, morphological and molecular. The present study aimed to include most species of Auchenipteridae (109 species), as well as several members of other siluriform families representing the outgroup (28 species comprising Mochokidae, Aspredinidae, Doradidae, Ariidae, Pimelodidae, Cetopsidae, and Diplomystidae) to embrace the greater diversity of forms existing within Siluriformes, providing a robust comparison between the taxa and providing therefore a series of information from different sources including morphology (261 characters) and molecular data (2814 characters based on four genes: COI, 16S, RAG2, and MyH6).The parsimony analysis based on combined data yielded 1691 maximally parsimonious trees and the strict consensus corroborated the monophyly of the superfamily Doradoidea, the family Auchenipteridae and its two subfamilies, Centromochlinae and Auchenipterinae as well. The new classificatory proposal also raises the number of tribes within Auchenipteridae from two to nine, evidencing the following major groups within Auchenipterinae: Liosomadoradini, Trachelyopterini, Asterophysini, Auchenipterini, and Ageneiosini; and in Centromochlinae: Gelanoglanini, Gephyromochlini, Centromochlini, and Glanidini. Additionally, most of auchenipterid genera were recovered as monophyletic, except for Centromochlus and Tatia. Centromochlus is restricted to only three species while Tatia is recovered as the most specious centromochline genus including the currently Centromochlus simplex, C. reticulatus and Pseudotatia parva, herein reallocated. To address the paraphyly of Centromochlus and Tatia, two new genera of Centromochlinae were proposed and a nomenclatural reorganization of the species in these genera was conducted. Furthermore, Glanidium and Trachycorystes resulted as paraphyletic, and a new combination for Glanidium leopardum, resurrecting Gephyromochlus, to allocate this taxa and a new genus of Auchenipterinae to allocate Trachycorystes menezesi were proposed. Notwithstanding, Ageneiosus was recovered as paraphyletic since Ageneiosus militaris was recovered as sister group to Ageneiosus and Tympanopleura. The paraphyly of Ageneiosus seems to be an artifact of morphological missing data for A. militaris and until these data are included in the analysis to readily test the position of this species, both genera are maintained as valid. A synapomorphy list and the diagnosis for each clade are presented under a new classification proposal. Furthermore, the interrelationship and monophyly of the genera and major groups are discussed and compared to previous propositions.

[Horlack]

PDF Source : http://repositorio.unesp.br/bitstream/h ... sAllowed=y

Title : Revisão Taxonômica de Neoplecostomus franciscoensis Langeani, 1990 (Loricariidae: Neoplecostominae)
Author : Arieli Matheus Cherobim,
Scholar : Universidade EstaDual Paulista "Julio de Mesquita Filho", Instituto de Biociencias, Campus de Sao José do Rio Preto, 23/03/2016



PS : Graphs, table, Taxonomy, etc...in Annexe, page 57 to 62

[Horlack]

Title : CYTOGENETIC AND DNA CONTENT IN 6 GENERA OF THE FAMILY CALLICHTHYIDAE (PISCES, SILURIFORMES)

Source : http://repositorio.unesp.br/handle/11449/37716

PDF Source : https://www.researchgate.net/profile/Cl ... ef76a6.pdf

Author
Oliveira, C.
Almeidatoledo, L. F.
Mori, L.
Toledo, S. A.

Date : 1993-04-01

Abstract

Cytogenetic studies involving conventional Giemsa staining, C-banding analysis and silver staining of NORs were performed on nine species belonging to six genera of the family Callichthyidae. The diploid number ranged from 2n = 44 to 2n = 100, the number of chromosomal pairs with NORs ranged from 1 to 4 and constitutive heterochromatin was mainly distributed in the centromeric and/or pericentromeric position of the chromosomes. The DNA content of erythrocytes from six species studied ranged from 1.18 +/- 0.07 to 2.77 +/- 0.22 pg/nucleus. The extensive variability in karyotypes and in nuclear DNA content detected are in accordance with the initial hypothesis that chromosome rearrangements and polyploidy have played a significant role in the evolutionary history of Callichthyidae

[Jools]

Just a reminder to append (i.e. reply) to this thread with any dissertations as opposed to having them all as their own topics in this section of the forum.

Thanks!

Jools

[bekateen]

Marburger, Sarah. 2015. Investigating mechanisms of genome expansion in Corydoradinae catfish. Ph.D. Dissertation, Prifysgol Bangor University

ABSTRACT:
The Corydoradinae catfish are a diverse sub-family of neo-tropical catfishes (order Siluriformes) with more than 170 species described to date. One of the most compelling features of this sub-family is the enormous amount of variation in genome size. With species containing between 0.5 pg and 4.8pg of DNA, variation is comparable to that found across the Teleostei as a whole. Previous phylogenetic analysis identified nine distinct lineages within the Corydoradinae, with more basal lineages possessing smaller genomes and with largest genome sizes found in the most derived lineages. To date, nothing is known about the mechanism that drove this genome expansion in the Corydoradinae, though Whole Genome Duplication (WGD) events have been suggested. Here, the incidence of WGD events has been investigated using a Hox gene and a restriction site associated DNA (RAD) sequencing data set. Both data sets identified a major duplication event at the base of the group, with additional duplication events occurring across the family. These duplication events were shown to have led to relaxed purifying selection and increased functional divergence of HoxA13a copies in the Corydoradinae compared with teleosts that have not undergone additional rounds of WGD. The RAD data set confirmed significant genome-wide shifts in duplicate, multi-haplotype regions across the Corydoradinae, and indicates that several species from lineages 6-9 are functionally polyploid, whereas species that underwent earlier WGDs have largely diploidized and are likely paleopolyploids. An increase in paralogous genes was noted, with Gene Ontology suggesting that gene retention in the Corydoradinae mirrors previously described retention in Tetraodon following the fish-specific genome duplication in the Teleostei. Intriguingly, the RAD data also identified a significant expansion of Transposable Elements (TEs), driven by a DNA TE superfamily (Tc1-Mariner). This expansion significantly contributed to the genome size variation, though to a lesser degree than the WGD events identified within this thesis.

P.S., @admin, FYI it seems that the Dissertations "sticky" has become "unstuck." I had a difficult time finding this thread because it no longer stays near the top (sticky) of the Taxonomy & Science News forum. Cheers, Eric

[Jools]

This topic has had glue freshly re-applied. Seems the sticky option can have a time limit applied after which its "adhesion" is removed.

Jools

[bekateen]

Thanks Jools. Well, isn't that an annoying characteristic!

Cheers, Eric

[bekateen]

Langoni, Andrei da Silveira. 2015. Biologia comparada alimentar de três lolicarídeos (OSTARIOPHYSI, SILURIFORMES) em diferentes riachos da Bacia do Alto Jacuí, Rio Grande do Sul, Brasil. PhD Dissertation, Universidade Federal do Rio Grande do Sul. Instituto de Biociências. Programa de Pós-Graduação em Biologia Animal.
Repository link: http://www.lume.ufrgs.br/handle/10183/131920
Full text (PDF): http://www.lume.ufrgs.br/bitstream/hand ... sequence=1

ABSTRACT
Study comparing the diet of three species of loricariids

Eurycheilichthys limulus

,

Ancistrus brevipinnis

, and

Hemiancistrus punctulatus

in different streams aiming to verify the presence or absence of food overlap between the species and between each species of size. Samples were conducted bimonthly by electrofishing technique from June / 2012 to June / 2013 In streams of high Jacuí basin, Rio Grande do Sul, Brazil. Through the content analysis feeds were identified 26 food items. In general, the three species showed the presence of four items that stood out: Detritus Organic, Bacillariophyta, Sediment, and Plant Material. In addition to these items, other items were representatively consumed differently for each species. The species Eurycheilichthys limulus consumed a high proportion of Simuliidae larvae and Chironomidae larvae, the species A. punctulatus and H. brevipinnis had a similar composition of the diet, Ancistrus brevipinnis presented as the main food items consumed: algae Oedogoniophyceae, larvae Chironomidae, Tecameba, algae Zygnemaphyceae, and Rotifers, while Hemiancistrus punctulatus presented as the main food items consumed algae Oedogoniophyceae, algae Zygnemaphyceae, Tecameba, larvae Chironomidae, and algae Cyanophycea. Species segregation can be observed by Analysis Coordinates Principal (PCoA). The items identified were responsible for this difference. All species and all size classes showed a high value of niche breadth. In general, these species have a low feeding overlap values. Some interactions between the species Eurycheilichthys limulus versus Hemiancistrus punctulatus and between Ancistrus brevipinnis versus Hemiancistrus punctulatus showed the presence of high values of food overlap indicating a competition, but the null model confirmed the niche partitioning between the species and classes size / species. Finally, it was found that there are food segregation between the three species of Siluriformes studied and that the sharing of resources between species is related to differential use of items in different stages of life.

RESUMO
Estudo comparando a dieta de três espécies de loricarídeos Eurycheilichthys limulus, Ancistrus brevipinnis e Hemiancistrus punctulatus, em diferentes riachos, com os objetivos de verificar a ocorrência ou não de sobreposição alimentar entre as espécies e entre as classe de tamanho de cada espécie. As coletas foram realizadas bimestralmente, pela técnica de pesca elétrica, a partir de junho / 2012 a junho / 2013, em riachos da bacia do alto Jacuí, Rio Grande do Sul, Brasil. Por meio da análise do conteúdo alimentar, foram identificados 26 itens alimentares. De modo geral, as três espécies apresentaram quatro itens que se destacaram: Detrito orgânico, Bacillariophyta, Sedimento e Material vegetal. Além disso, a espécie Eurycheilichthys limulus consumiu uma elevada proporção de larvas de Simuliidae e Chironomidae, e as espécies Ancistrus brevipinnis e Hemiancistrus punctulatus apresentaram uma composição da dieta semelhante. Ancistrus brevipinnis apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, larva de Chironomidae, Tecameba, alga Zygnemaphyceae e Rotífera, enquanto Hemiancistrus punctulatus apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, alga Zygnemaphyceae, Tecameba, larva de Chironomidae e alga Cyanophyceae. Foram identificados os itens responsáveis por essa diferença. Todas as espécies e classes de tamanho apresentaram um alto valor de amplitude de nicho e, na maioria das interações, um baixo valor de sobreposição alimentar. Algumas interações entre as espécies Eurycheilichthys limulus versus Hemiancistrus punctulatus e Ancistrus brevipinnis versus H. punctulatus apresentaram valores altos de sobreposição alimentar, o que poderia indicar uma competição, porém o modelo nulo mostrou o compartilhamento de recursos entre as espécies e classes de tamanho/espécies. Por fim, constatou-se que há segregação alimentar entre as três espécies de Siluriformes estudadas e que a partilha de recursos entre as espécies está relacionada à utilização diferencial de itens em diferentes fases da vida.

Red text = typographical error where specific epithets for Ancistrus and Hemiancistrus are reversed.

Besides its research value, this paper has nice photos of the habitats of these fish, and photos of the fish.