NORTH CAROLINA MARINE ALGAE. VI. SOME CERAMIALES (RHODOPHYTA), INCLUDING A NEW SPECIES OF DIPTEROSIPHONIA1

Six members of the Ceramiales are added to the flora of North Carolina. Two of these, Acrosorium uncinatum (Turner) Kylin and, Rhododictyon bermudensis Taylor, are also reported from South Carolina for the first time. One species, Mesothamnion boergeseni Joly, was previously known only from Brazil and another, Dipterosiphonia reversa sp. nov., is added to the algal literature for the first time. Evidence is presented for the reassignment of R. bermudensis from the Dasyaceae to the Ceramiaceae.     

VAUCHERIAE OF NORTH CAROLINA. I. MARINE AND BRACKISH WATER SPECIES1

Marine Vaucheriae of North Carolina were investigated in the field and in culture for 4 years. Of the 11 species collected, 4 are new records for North Carolina and 2 are previously unreported species. A new section is established, Acrandrae, to contain Vaucheria acrandra sp. nov. and Vaucheria adela sp. nov. The diagnostic character of the new section is the production of androphores directly from the terminal portion of the main filament rather than from a special cell produced laterally on the filament as in the section Androphorae.     

FIELD AND CULTURE STUDIES ON GROWTH AND REPRODUCTION OF CALLITHAMNION BYSSOIDES (RHODOPHYTA,CERAMIALES) IN NORTH CAROLINA1,2

The life history of Callithamnion byssoides Arnott ex Harv. in Hook. from North Carolina is shown to be of the Polysiphonia-type. Cross-gradient light-temperature culture in 8:16 and 14:10 LD cycles was utilized to investigate the effects of light intensity, temperature and day-length on growth and reproduction. Carposporophyte and tetrasporangium development were controlled by total light energy rather than photoperiod. Results of these studies explain the observed seasonal periodicity of growth and reproduction on the North Carolina coast. Variations between these results and previously published data for this species in Texas are explained in terms of ecotypic differentiation.     

BENTHIC DIATOMS FROM THE NORTH CAROLINA CONTINENTAL SHELF: INNER AND MID SHELF1

Sediment samples collected by SCUBA divers at two times and three sites on inner and middle continental shelf of North Carolina a well-developed benthic diatom flora. The most abundant species included the pennate forms Cocconeis disculoides, Diploneis papula, Naticula pullus, Delphineis surrirella, Amphora sublaevis, and A. tenerrima. Biomass of this distinct benthic microflora ranged from 16 to 97 mg chl a + m^?2 and is comparable to sediment chlorophyll a values reported in previous studies.     

GRACILARIA HUMMII SP. NOV. (GRACILARIALES,RHODOPHYTA), A NEW NAME FOR THE AGAROPHYTE “GRACILARIA CONFERVOIDES” HARVESTED IN NORTH CAROLINA DURING WORLD WAR II1

Gracilaria hummii Hommers. et Freshwater is proposed as a new name for the inshore cylindrical species found in North Carolina that was treated as Gracilaria confervoides (L.) Grev. during World War II, and more recently as G. verrucosa (Huds.) Papenf. Molecular evidence places G. hummii in the Gracilis‐group in Gracilaria together with G. gracilis (Stackh.) Steentoft, L. M. Irvine et Farnham, the name currently applied to specimens formerly identified as G. confervoides and G. verrucosa. G. hummii differs from G. gracilis in possessing shallower male conceptacles in which the spermatangial filament originates from a surface cortical cell rather than from a subcortical cell. The cystocarps are similar, except that the gonimoblasts of G. hummii are attached to the base of the pericarp by numerous, prominent thickened terminal tubular cells and because terminal tubular cells are absent above the midregion of the cystocarp or in the vicinity of the ostiole. The gonimoblasts are subtended by a bundle of longitudinally oriented, thick‐walled secondary filaments of a type that has not been described before in Gracilaria but that may be characteristic of some other species. G. hummii occupies a basal position in the Gracilis‐group and is distinct from all other cylindrical North Carolina Gracilaria species, according to the molecular and morphological evidence.     

THE CYTO-ECOLOGY OF FOUR SPECIES OF TRILLIUM FROM WESTERN NORTH CAROLINA

The major center of variability in the genus Trillium occurs in the southern Appalachian mountains of the eastern United States. The karyotypic variation existing within T. cuneatum Raf., T. grandiflorum (Michx.) Salisb., T. erectum L., and T. gleasoni Fern., the four most abundant Trillium species in western North Carolina, was analyzed and compared with the variation in gross morphology and the ecological associations of the respective species. The number of types of each kind of chromosome (A-E), as exhibited following “nucleic acid starvation” by cold treatment, varied widely from species to species. Chromosome types varied within each species and within populations in the numbers, sizes, and positions of euchromatic and heterochromatic segments. No 10-chromosome karyotype and only one 5-chromosome complement was found to be duplicated in any two plants which belonged to different species. Trillium cuneatum with eight chromosome types was morphologically stable and occurred in a limited geographic area. Trillium gleasoni, characteristically adapted to elevations near 2,000 feet, contained 32 chromosome types and exhibited a high morphological variability. Trillium erectum (25 types) and T. grandiflorum (23 types) were also intermediate in morphological variability. These two species had the widest geographical range. Karyotypes were analyzed from pure stands of each of the four species and for each species from mixed stands of two or more of the species growing in close association. These Trillium species are maintaining a high level of karyotypic and gross morphological variability within comparatively limited geographical areas. None of the observed karyotypes in any species is likely to have arisen by recent interspecific hybridization. The composite karyotype of each species could be used as an aid to classification in the genus Trillium.     

GIFFORDIA ONSLOWENSIS SP. NOV. (PHAEOPHYCEAE) FROM THE NORTH CAROLINA CONTINENTAL SHELF AND THE RELATIONSHIP BETWEEN GIFFORDIA AND ACINETOSPORA1

Giffordia onslowensis sp. nov. is described from the North Carolina continental shelf. This alga is distinct in having upper filaments which are profusely branched, with branches borne at the tops of cells at narrow angles, and lower filaments which are sparsely branched, with branches borne at the middle of cells at wide angles. It is somewhat intermediate between Acinetospora and Giffordia because of the morphology of the lower branches. Morphological variability of Giffordia in culture is numerically documented and similarities between Giffordia spp. and Acinetospora in culture are interpreted as artifacts of altered or incomplete development. It is concluded that Acinetospora, Giffordia, and Ectocarpus should be retained as separate genera.     

KARYOLOGICAL STUDIES OF THREE SPECIES OF SCYTOSIPHONACEAE (PHAEOPHYTA) FROM COASTAL NORTH CAROLINA1

Chromosome numbers for three species of Scytosiphonaceae from the warm temperate coast of North Carolina are presented. Petalonia fascia (O. F. Mueller) Kuntze, P. zosterifolia (Reinke) Kuntze, and Scytosiphon lomentaria (Lyngbye) C. Agardh were all found to have twenty-two chromosomes in both macro- and microthallus stages. The uniformity of chromosome numbers and morphology for all three taxa suggest a close genetic relationship and possible common ancestry. Evidence of synchronous mitotic divisions is presented for the first time in the Phaeophyta. Both field collected and culture material of P. fascia and P. zosterifolia exhibited a 2–4 h post-sunset peak in nuclear divisions. In actively growing macrothalli, up to 8% of the observed cells were found in some stage of mitosis. Data suggest that mitosis and the entire sequence of cytokinesis require approximately 2 h.     

MORE EVIDENCE FOR CONIFER DIVERSITY IN THE UPPER TRIASSIC OF NORTH CAROLINA

An ovulate strobilus from the Upper Triassic Deep River Basin, North Carolina, has helically arranged, loosely aggregated, elongated, spatulate bracts with axillary ovule-bearing appendages with about 8–10 ovules attached in two lateral rows, with outwardly directed micropyles. The axillary ovuliferous appendage is homologous with the voltzialean fertile dwarf shoot, but probably not directly evolved from it. More credible is a suggested origin from a completely fertile axillary appendage such as that of the Lower Permian Trichopitys. The occurrence of this cone, Metridiostrobus palissyaeoides, gen. and sp. nov., along with Compsostrobus neotericus and Voltzia andrewsii, reflects considerable diversity among conifer ovulate cones during the Upper Triassic.     

REPRODUCTIVE SEASONALITY OF WESTERN ATLANTIC BOTTLENOSE DOLPHINS OFF NORTH CAROLINA, U.S.A.

We describe reproductive seasonality of bottlenose dolphins in North Carolina (NC), U.S.A., using strandings data from the entire coast of NC and sighting data from Beaufort, NC and by estimating dates of birth of known females. We found a strong peak of neonate strandings in the spring (April-May), and low levels of neonate strandings in the fall and winter. The distribution of neonate strandings was significantly different from a uniform distribution ( P < 0.001, K = 3.8). We found a unimodal distribution of 282 sightings of neonates with a diffuse peak in the summer. The temporal distribution of sightings of neonates departed significantly from a uniform distribution (P < 0.001, K = 5.1). Estimated birth dates of neonates from known females occurred in May ( n = 6) and June ( n = 4), with a single fall birth. These methods shed light on bottlenose reproductive patterns and underscore the value of using information from multiple types of data. Clarification of bottlenose dolphin reproductive patterns, such as the seasonality of birth, may enhance our understanding of the population structure of this species in the mid-Atlantic region.     

GENETIC VARIATION IN PLANT-INSECT ASSOCIATIONS: SURVIVAL OF LEPTINOTARSA DECEMLINEATA POPULATIONS ON SOLANUM CAROLINENSE

Populations of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), from the east coast of the United States differ in their ability to survive on a wild host, Solanum carolinense (Solanaceae), but not on their most important cultivated host, Solanum tuberosum. On the wild host, the North Carolina population survived best, while populations from Virginia, New Jersey, and Connecticut exhibited uniformly low survival. Formal genetic studies of populations from Connecticut and North Carolina demonstrated heritable variation in the ability to survive on S. carolinense both between and within populations; the North Carolina population had the higher heritability for this trait. Overall, there was no genetic variation between populations or within the North Carolina population for survival on S. tuberosum, but such variation existed within the Connecticut population. Hybrids and backcrosses between these two lines all survived at intermediate levels, although survivorship did not appear to be inherited additively. Differences in survival were greater than differences in adult weight at emergence and development time of the survivors. Leptinotarsa decemlineata was first reported from North Carolina less than 100 years ago. The rapid expansion of L. decemlineata's host range in North Carolina is attributed to the poor synchrony between the insect and S. tuberosum compared to more northerly locations. In contrast to the prediction of a strong negative correlation in fitness on different host species, the ability of L. decemlineata to survive on S. carolinense was not correlated with that on S. tuberosum. Adult weight and female development time were significantly positively correlated across hosts. Our results are in accord with most previous studies in which strong negative correlations in fitness of specialized phytophagous insects feeding on different hosts were expected, sought, but not found.     

NEW ENDOLITHIC CYANOPHYTES FROM THE NORTH ATLANTIC OCEAN. II. HYELLA GIGAS LUKAS & GOLUBIC SP. NOV. FROM THE FLORIDA CONTINENTAL MARGIN1

A new species of endolithic cyanophyte, Hyella gigas Lukas and Golubic (Order: Pleurocapsales), differs from other species of Hyella by its larger cell and filament dimensions and its laminated, often pigmented sheath. It bores into mollusk shells and other marine carbonate substrates on the east coast of North America, the Bahama Islands and the Northern Mediterranean Sea, where it is found from near mean low water down to 25 m depth. This comparatively shallow maximum depth is probably due to the limited capacity of Hyella gigas to adapt to changing light quality and intensity. We reject the suppression of the genus Hyella as proposed by Drouet and Daily.     

Hesionides riegerorum n. sp., a New Interstitial Freshwater Polychaete from the United States

Hesionides riegerorum n. sp. is a new freshwater polychaete species. It was found in considerable numbers in the interstitial habitat of sandy banks of the Chowan River in North Carolina, USA. There are no general differences in the organization and behavior compared to the marine species of this genus. The new species, however, is unequivocally distinguished from them by slight quantitative differences and more striking qualitative features. The localities not far from the coast point to an immigration path for this freshwater polychaete that has been shown also for most of the other marine interstitial immigrants: directly from sandy intertidal beaches along brackish estuaries into the limnopsammal.     

FERTILE CONIFEROPHYTE REMAINS FROM THE LATE TRIASSIC DEEP RIVER BASIN,NORTH CAROLINA

Seed cones (Compsostrobus neotericus gen. et sp. nov.), pollen cones, and vegetative remains of coniferophytes occur in Upper Triassic rocks of the Deep River Basin (Pekin Formation) of Central North Carolina. Seed cones have spatulate ovuliferous scales, each with two ovules and subtended by an elongated bract with an attenuate tip. Cuticle of seed cones resembles that of leaves on vegetative axes. Slender leaves are borne along two sides of the axis. Pollen cones have helically arranged microsporophylls, each with two abaxial sporangia bearing pollen grains of the Alisporites type. Seed cones, pollen cones, and vegetative remains suggest a coniferophyte very modern in aspect.     

VAUCHERIA SYNANDRA (XANTHOPHYCEAE,VAUCHERIALES): FIRST RECORD FOR NORTH AMERICA1

The brackish water species, Vaucheria synandra Woronin, common to Europe, is reported for the first time in North America from a coastal swamp area in Louisiana. The material from Louisiana is described and pictured, and is compared to other Vaucheria species with androphores.     

RECENT VERSUS RELIC: DISCERNING THE GENETIC SIGNATURE OF FUCUS VESICULOSUS (HETEROKONTOPHYTA; PHAEOPHYCEAE) IN THE NORTHWESTERN ATLANTIC1

Fucus vesiculosus L. is one of the most widespread macrophytes in the northwestern Atlantic, ranging from North Carolina (USA) to Greenland (DK). We investigated genetic diversity, population differentiation, patterns of isolation by distance, and putative glacial refugial populations across seven locations from North Carolina (USA) to Cape Breton Island, Nova Scotia (Canada), with microsatellite analyses. Distinct northern versus southern (Delaware–North Carolina) populations were revealed by microsatellite data. Five of six microsatellite loci were fixed in populations in North Carolina, suggesting a recent founder event or a bottleneck, and the same homozygous genotype was found in herbarium materials collected on the North Carolina coast from more than 60 years ago. An additional set of individuals from the northern limit in Greenland was included in our analysis of mitochondrial intergenic spacer (mt IGS) haplotypes in the northwestern Atlantic. Remarkably, 184 of 188 F. vesiculosus specimens from North Carolina to Greenland shared the same haplotype. Recent colonization of the North American shore from Europe is hypothesized based upon the ubiquity of this common haplotype, which was earlier reported from Europe.     

A new species of Acentrella Bengtsson (Ephemeroptera: Baetidae) from Great Smoky Mountains National Park,USA

Acentrella barbarae sp. n. is described from eggs, larvae, and imagines collected from Great Smoky Mountains National Park, North Carolina and Tennessee, USA. Larvae were collected from cobble-pebble substrate in stream rapids. Life stages were associated by rearing. Eggs have longitudinal chorionic ridges with small, longitudinal furrows. Larvae are distinguished by having segment 3 of the labial palp apically rounded, abdominal terga with posteromedian projections, and tibiae and tarsi with relatively short setae on the outer margins. Imagines are distinguished by the colouration and posterior elevation of abdominal terga. Other Acentrella larvae occur in the same streams as the new species, including A. parvula, which we report from Tennessee for the first time. We provide an updated key to the larvae of North American Acentrella species.