2007 Abstracts
Phylogenetic analysis of RTA-clade spiders (Araneae: Entelegynae) using molecular sequence data
Alexander ArguelloJeremy Miller
St. Mary's College, St. Mary's City, MD
Department of Entomology, California Academy of Sciences, CA
We propose a novel phylogenetic framework for a problematic group of spiders for which family-level relationships have yet to be resolved. The RTA-clade, named for the retrolateral tibial apophysis (RTA) on the male copulatory organ, is a major lineage representing approximately 52% (>20,000 described species) of worldwide spider diversity. This study re-examines the RTA-clade using a combination of new sequence data (36 individuals) and Genbank sequence data (37 individuals) for one mitochondrial (COI) and three nuclear gene fragments (H3, 28S, and 18S) analyzed under Bayesian and parsimony criteria. We include all subfamilies for the most controversial RTA-clade families (e.g., Agelenidae, Amaurobiidae, Cybaeidae, Desidae, Dictynidae, and Hahniidae). This is the first phylogenetic study to include the South African endemic subfamily Penestominae and the California endemic subfamily Zanoyminae. Despite the presence of a well-developed RTA, penestomines have historically been placed in the Eresidae, a non-RTA-clade family. Our molecular analysis places penestomines within the RTA-clade, not with other eresids. Our results also support the traditional placement of zanomyines within Amaurobiidae. However, we refute the hypothesis that Zanomyinae and the subfamily Coelotinae are close relatives. Instead, our results show that the Coelotinae belongs to the family Agelenidae rather than Amaurobiidae. Preliminary results also suggest paraphyly of several RTA-clade spider families. These results are credible because the spider families in question are morphologically heterogeneous and undiagnosable as currently defined. By providing a molecular phylogeny for the RTA-clade, this study presents a guide for how RTA-spider families might be re-classified as monophyletic groups and advances our understanding of the evolutionary relationships among these families.
*****We acknowledge generous funding from the NSF REU program*****
Determining the relationship between Phlyctimantis and Kassina (Anura: Hyperoliidae) with a molecular approach: A preliminary analysis
Noelle BittnerRobert Drewes
Smith College, Northampton, MA
Department of Herpetology, California Academy of Sciences, CA
The African Tree Frogs (Hyperoliidae) are a large and diverse family found throughout much of Africa south of the Sahara. Past studies (Drewes, 1984; Channing 1988) suggest a basal monophyletic clade within the Hyperoliidae containing five genera including Kassina, Kassinula, Paracassina, Phlyctimantis, and Semnodactylus. Four of these are well supported by morphological traits. However, there are no synapomorphies supporting the fifth genus, Phlyctimantis Laurent and Combaz (4 sp.). In Drewes (1984) Phlyctimantis is an uncorroborated node. Kassina Girard (13 sp.), a highly variable genus both in appearance and lifestyle, is likely the sister group to Phlyctimantis. This relationship is supported by similarities in appearances and the mating calls of males in both genera. We examined a novel morphological character originally thought to be exclusive to Phlyctimantis and one Kassina, K .maculata, in an attempt to elucidate the relationship between the two. Upon further inspection, the structure was found in additional species of Kassina. These findings lead us to question the proper placement of K. maculata, which resembles other species within Phlyctimantis, and the validity of Phlyctimantis as a genus. To help determine whether the two genera are supported as separate entities, we compared mitochondrial sequences of the 12s rRNA gene of P. boulengeri, P. verrucosus, K. cassinoides, K. decorata, K. fuscus, K. maculata and K. senegalensis. Preliminary analysis of these data yielded a molecular phylogeny supporting Phlyctimantis as a cohesive genus.
*****We acknowledge generous funding from the Robert T. Wallace endowment*****
Multiple origins of respiratory structures in sea urchins
Cara Marie BreslinRich Mooi
University of California at Santa Cruz, Santa Cruz, CA
Department of Invertebrate Zoology and Geology, California Academy of Sciences, CA
The sea urchin clade Irregularia consists of the irregular sea urchins such as heart urchins (Spatangoida), lamp urchins (“cassiduloids”), and sand dollars (Clypeasteroida). Many of these sea urchins possess petaloids, which are flower-like respiratory structures on the top (aboral) surface of these echinoids. Petaloids are made up columns of closely packed, gill-like tube feet. Each tube foot sits on a pair of pores that pierce the calcite plates making up the body wall.
Although phylogenies exist for some of the groups within the Irregularia, no one has attempted to put all these trees together to present an overall phylogeny. By combining previously published trees from different literature sources, we produced a phylogeny that links all the major clades of irregular urchins, both extant and fossil. Our analysis of more than 60 taxa demonstrates that petaloids evolved in the Irregularia more than once. Critical to this discovery is the placement of extinct taxa, many of which lack petaloids, at the bases of each of the major branches in the phylogeny. Therefore, in spite of superficial similarities, petaloids in the clade incorporating the heart urchins are not homologous to the petaloids in the clade containing oligopygoids, sand dollars, and lamp urchins. Closer examination revealed differences in the position of respiratory pores between heart urchins and other irregular urchins. In heart urchins, pores are found in the center of the plate, in clypeasteroids and oligopygoids they are found along the sutures between the plates. This has major implications for our understanding of the evolution of respiratory structures in echinoids, as well as for the definition of criteria that lead to the recognition of petaloids.
*****We acknowledge generous funding from the NSF REU program*****
Comparative pollen morphology of the genus Symplocos
Adam BruehlPeter Fritsch
Guilford College, Greensboro, NC
Department of Botany, California Academy of Sciences, CA
The genus Symplocos comprises about 325 species of flowering plants found in tropical to sub-tropical regions around the world. Pollen samples from thirty-nine representative species of Symplocos were examined through scanning electron microscopy to evaluate the significance of pollen morphology to the systematics of the genus. Symplocos pollen morphology varies greatly throughout the genus with geometry ranging from oblate to spheroidal, aperture morphology ranging from tri-colporate to tri-porate, and equatorial diameters ranging from 20µm to 45µm. These characteristics appear to carry significant phylogenetic signal. In the largest New World clade, Symplocastrum (including Neosymplocos), pollen grains are primarily spheroidal to sub-spheroidal, with a sub-circular/triangular to circular equatorial outlines. Nearly all are tri-colporate; however, a few are bi-colporate with an elliptical equatorial outline. This clade is unique in that many species exhibit a primarily psilate (smooth) ornamentation and rarely if ever have any protruding ornamentation. Another New World clade, Urbaniocharis, differs from other New World clades by exhibiting a primarily rugulate (large undulating ridges) ornamentation. Species in Epigenia, another New World clade, differ from Symplocastrum by exhibiting protruding ornamentation. Also, whereas most species primarily exhibit the tri-colporate morphology, many in Epigenia also produce some 4-colporate grains or 3-colporate grains with one additional pore. Hopea, the main Old World clade, produces pollen that is small, oblate, and triangular in comparison to New World clades, and also exhibits a highly variable ornamentation. We found that Symplocos pollen exhibits a strong phylogenetic signal in terms of ornamentation, shape, and aperture morphology, that roughly correlates with established clades in Symplocos.
*****We acknowledge generous funding from the NSF REU program*****
Family drama: Resolving the nudibranch family Aeolidiidae
Alexis JacksonTerrence M. Gosliner
Yale University, CT
Department of Invertebrate Zoology & Geology, California Academy of Sciences, CA
Within the order Nudibranchia, the family Aeolidiidae is defined by pectinate jaws and by the location of the anus. Taxonomists have been unable to resolve the family into genera due to the great extent of parallel evolution that has occurred. Efforts to reclassify genera based solely on one to two morphological characteristics failed to consistently hold in systematic studies. In this study, I compiled extensive morphological data on 10 aeolidiids and 4 outgroups, based on external morphology and characteristics of the reproductive tract, oral glands, jaws and radular teeth. I also obtained molecular data by isolating the 16S and CO1 genes. Morphological characteristics surrounding the presence of oral glands, the type of rhinophores, the masticatory edge of the jaw, the shape of the teeth and texture of the oral glands proved to be strong phylogenetic characters. Morphological trees reveal that Aeolidiidae is a monophyletic family and that the genera Baeolidia and Berghia are sister taxa. They also reveal that rhinophores can provide significant phylogenetic signal, especially for those species with papillate rhinophores. Molecular data are currently being analyzed and ideally should confirm the aforementioned morphological trends.
*****We acknowledge generous funding from the NSF REU program*****
Analyzing multiple morphological characteristics of South African Scrophulariacea inflorescences
Lucinda MolnarKim Steiner
University of North Carolina, Asheville, NC
Department of Botany, California Academy of Sciences, CA
** Abstract withheld by authors **
*****We acknowledge generous funding from the NSF REU program*****
Circumtropical biogeographical survey of octocorals
Caitlin MorrisonGary Williams
Skyline College, San Bruno, CA
Department of Invertebrate Zoology & Geology, California Academy of Sciences, CA
Octocorals are anthozoans with eight pinnate tentacles and calcitic spicules. Many past studies of corals have overlooked octocorals, focusing instead on hermatypic hard corals. This bias is due in part to the difficulty of identifying and classifying octocorals, and in part to the idea that hermatypic hard corals are more important ecologically, as they are the predominant lime-secreting reef builders. In addition, most past studies on octocorals dealt mainly with taxonomy, and hence octocoral biogeography is not well understood.
In this study I compiled and analyzed data on octocoral biogeography using both the literature and recent field studies conducted by scientists at the California Academy of Sciences. Goals of biogeographical analyses such as this one include identifying broad distribution patterns and biogeographic regions that may illuminate past vicariant events and provide insight into the phylogeny of the taxa studied. In addition, biogeographic studies are also important in identifying regions of high endemism and diversity, helping to develop priorities for conservation. This particular survey identified two distinct biogeographic regions of octocorals. All of the regions studied in the Indian Ocean, the Western Pacific, and the central Pacific (together known as the Indo-Pacific) had similar faunal distributions and taxonomic compositions, which were distinctly different from the fauna found in the Atlantic. Interestingly, the Eastern Pacific fauna is more closely allied faunistically to the Atlantic regions than it is to those in the Indo-Pacific. This is most likely due to the large body of deep water separating the central Pacific from the eastern Pacific. We also found the Indo-Pacific to be much more biologically diverse than the Eastern Pacific and Atlantic regions. As of yet, there is not sufficient data to accurately identify areas of high endemism. However, we hope that our descriptions of distributional patterns and areas of high diversity will provide the framework for further studies.
*****We acknowledge generous funding from the NSF REU program*****
Illustrating the fishes of Turkmenistan
Bricelyn StrauchDavid Neely
University of Georgia, GA
Department of Ichthyology, California Academy of Sciences, CA
The fishes of Turkmenistan are a very diverse group. Found in the Amu Darya and Syr Darya rivers as well as the Aral Sea, many of these fishes have been introduced from China. Most are endangered because of Turkmenistan's major industry, cotton farming. Cotton farming not only causes pollution of waterways, but also, because of the need for irrigation in the dry climate of Turkmenistan, drains water out of the rivers and Aral Sea. To document their diversity, we are preparing a field guide of the fishes of Turkmenistan that includes both color photographs and detailed illustrations. Over the course of the internship, I have completed about 17 graphite drawings using a camera lucida, corresponding to one-third of the drawings needed to finish the guide. Some species illustrated are Perca fluviatilia (perch), Cyprinus carpio (carp), and Silurus glanis (catfish). The purpose of these illustrations is not only to portray the major identifying characteristics of these diverse fishes, but also to aid in creating a comprehensive guide of a particular fauna that has never been fully available or examined.
*****We acknowledge generous funding from the Robert T. Wallace endowment*****
A genus of hylid frog new to the fauna of Trinidad and a molecular phylogeny of Trinidadian hylids
April WrightRobin Lawson and Brian Simison
St. Olaf College, MN
Center for Comparative Genomics, California Academy of Sciences, CA
The island republic of Trinidad and Tobago offers a unique opportunity for biogeographical study. Until roughly 100 million years ago, Trinidad was geographically connected to the South American continent while Tobago was part of the northern Caribbean plate. Therefore, the fauna of the two islands have different geographic origins, but at their present location, migration (by rafting) is possible between the two islands. Studying species on the islands thus offers a real-time look at the effect of migration on phylogenetic relationships.
This study used 12S ribosomal DNA sequence data to identify an unknown hylid frog collected on Trinidad. This South American frog had not been known to exist on the islands of Trinidad and Tobago previously, providing an opportunity to examine the relationship of this newcomer to eight South American taxa collected on the islands. We are currently analyzing our DNA sequences to get a phylogenetic tree of our sample specimens. Our results will offer insight on the effects of migration between islands on phylogenetic relationships.
*****We acknowledge generous funding from the NSF REU program*****