We have conducted the first phylogenetic study to our knowledge of Zoanthus in the northern hemisphere by sequencing and analysing the mitochondrial cytochrome oxidase subunit 1 (COI) gene. Various unidentified Zoanthus specimens and samples of what have been assumed to be four discrete species (Z. pacificus, Z. sansibaricus, Z. gnophodes, Z. erythrochloros) were collected from four field sites in Kagoshima Prefecture, Japan. Based on our obtained COI gene sequences, all but one of our collected Zoanthus samples appear to be conspecific, with nearly 100.00% base pair matching. Genetic results are further backed up by collected polyp diameter, tentacle count, and mesentary count data. These results indicate a need to reconsider and re-analyze current Zoanthus classification and identification. Possible reasons for the large morphological variation in the same genotype in Zoanthus are also discussed.

Many current designs contain a large number of standard cells intermixed with larger macro blocks. The range of size in these "mixed block" designs complicates the placement process considerably; traditional methods produce results that are far from satisfactory.In this paper we extend the traditional recursive bisection standard cell placement tool Feng Shui to directly consider mixed block designs. On a set of recent benchmarks, the new version obtains placements with wire lengths substantially lower than other current tools. Compared to Feng Shui 2.4, the placements of a Capo-based approach have 29% higher wire lengths, while the placements of mPG are 26% higher. Run times of our tool are also lower, and the general approach is scalable.

In this paper, we present improvements to recursive bisection based placement. In contrast to prior work, our horizontal cut lines are not restricted to row boundaries; this avoids a "narrow region" problem. To support these new cut line positions, a dynamic programming based legalization algorithm has been developed. The combination of these has improved the stability and lowered the wire lengths produced by our Feng Shui placement tool.On benchmarks derived from industry partitioning examples, our results are close to those of the annealing based tool Dragon, while taking only a fraction of the run time. On synthetic benchmarks, our wire lengths are nearly 23% better than those of Dragon. For both benchmark suites, our results are substantially better than those of the recursive bisection based tool Capo and the analytic placement tool Kraftwerk.

No clear method of identifying species in the zoanthid genus Zoanthus has been established, due in part to the morphological plasticity of this genus (e.g., in polyp and colony form, oral disk color, tentacle number). Previous research utilizing the mitochondrial cytochrome oxidase I gene (COI) as a phylogenetic marker indicated that Zoanthus spp. in Japan may consist of only one or two species, despite a bewildering variety of observed morphotypes. Here we have utilized not only COI but also mitochondrial 16S ribosomal DNA (mt 16S rDNA) in order to clarify the extent of Zoanthus species diversity in southern Japan. Our molecular genetic results clearly show the presence of three monophyletic Zoanthus species groups with varying levels of morphological plasticity, including the new species Z. gigantus n. sp. and Z. kuroshio n. sp. We describe all three species found in this study, and identify potential morphological characters (coenenchyme and polyp structure as well as polyp external surface pigmentation patterns) useful in Zoanthus species identification. A morphological dichotomous key is provided to assist in field species identification.

Interspecific hybridization has been proposed as a possible explanation for the incredible diversity seen in reef-dwelling corals, but until now little proof of such hybridization in other reef-dwelling anthozoans has been reported. Without further observation of hybridization, the question of such a phenomenon being widespread in Anthozoa remains. Here we have examined the mitochondrial cytochrome oxidase I gene (COI) and the nuclear internal transcribed spacer of ribosomal DNA (ITS-rDNA) from three species of the mass-spawning, encrusting anemone genus Zoanthus (Z. sansibaricus, Z. kuroshio, Z. gigantus) to investigate possible hybridization. The three species coexist at two of three sampling locations in southern Japan. Zoanthus spp. ITS-rDNA region spacers (ITS-1 and ITS-2) were shown to have very high rates of divergence. At locations where all three species co-existed, several of our sampled Z. sansibaricus individuals (with identical "sansi" COI sequences) possessed two very divergent (i.e., species-level difference) ITS-rDNA alleles, the expected "sansi" allele and the divergent "B" allele. Additionally, two Z. sansibaricus individuals possessed only "B" alleles despite having "sansi" COI sequences. These results indicate that Z. sansibaricus has possibly experienced interspecific hybridization at least once with a Zoanthus partner possessing the "B" allele, and that these resulting hybrids may also sexually reproduce, demonstrating potential hybridization occurring in the order Zoantharia (Hexacorallia).