Pityrocarpa Moniliformis Research Articles

Phylogenetic Study of the Genus Piptadenia (Mimosoideae: Leguminosae) using Plastid trnL-F and trnK/matK Sequence Data

We undertook a phylogenetic study of the genus Piptadenia with a sample of 18 of ca. 27 recognized species using DNA sequences from the plastid trnL-F and trnK/matK regions. Parsimony jackknife results support the hypothesis that Piptadenia is polyphyletic and that there are three independent lineages. The largest groups of species form a monophyletic lineage that is sister to Mimosa and corresponds closely to Piptadenia section Piptadenia sensu Barneby. Three species (P. obliqua, P. moniliformis, and P. leucoxylon) of section Pityrocarpa are sister to species of Pseudopiptadenia in a lineage with Parapiptadenia, Microlobius and Stryphnodendron. Piptadenia viridiflora is distantly related to sects. Piptadenia and Pityrocarpa. Section Piptadenia is characterized by the presence of prickles (aculei), a potential synapomorphy linking it to Mimosa, and exserted, racemose or paniculiform inflorescences of aggregated spikes. Piptadenia viridiflora has stipular spines and 1-2 axillary, spicate primary inflorescences. Species of sect. Pityrocarpa are unarmed trees (sometimes with hardened, persistent stipules) whose flowers have recurved petals and an ovary on a long gynophore. We recommend that Piptadenia viridiflora be removed to a new genus, and that Piptadenia be restricted to the other species of sect. Piptadenia. We resurrect the generic name Pityrocarpa to encompass the Pityrocarpa clade and make the following new combinations: Pityrocarpa moniliformis, Pityrocarpa obliqua ssp. brasiliensis, and Pityrocarpa leucoxylon.

Cleaning Stations as Water Holes, Garbage Dumps, and Sites for the Evolution of Reciprocal Altriusm?

Since the publication of Limbaugh's (1961) popular account of cleaning symbiosis among fishes, the topic has attracted considerable attention from the scientific community (e.g., Youngbluth 1968; Hobson 1969, 1971; Abel 1971; Ayling and Grace 1971; Losey 1971, 1972a, 1972b, 1974a, 1974b; Losey and Margules 1974; Wyman and Ward 1972; Potts 1973a, 1973b; Darcy et al. 1974; Sulak 1975). Cleaning behavior involves feeding by cleaner organisms on ectoparasites, scales, mucus, and other materials from the body surfaces and oral and gill cavities of "cooperating" host fishes. Members of many marine and freshwater fish families have been documented as cleaners (Labridae, Gobiidae, Chaetodontidae, Cichlidae, Centrarchidae, etc.). Within most cleaning associations, many different host species interact with a cleaner and perform similar behaviors. Thus cleaning symbiosis serves as an excellent example of a widespread multiple symbiosis, which may well have involved convergent evolution of cleaning organisms and coevolution of cleaners, hosts, and ectoparasites. The value of such an important example, however, requires the correction of earlier papers that now appear inaccurate in view of recent results and comment on recent papers that are misleading because they have largely ignored the most recent studies. Hobson (1969, 1971) has begun this task by presenting data and arguments against accepting many of the broad but untested generalizations about cleaning symbiosis which have been accepted as facts, including claims of substantial differences between cleaners and between cleaning behaviors in temperate and tropical seas and widely accepted but unsubstantiated claims that many good sport-fishing grounds exist because fishes aggregate in these areas in order to be cleaned. We will address two areas related to past and recent research on cleaning symbiosis: (1) the importance of cleaning to reef ecology; (2) the validity of cleaning as an example of reciprocal altruism. We will also consider some minor inaccuracies that remain in the literature and frequently acquire much importance when cited or reviewed.