Female Thalli Research Articles

The biology of Marchantia polymorpha subsp. ruderalis Bischl. & Boissel. Dub in nature.

Though used as the model liverwort in culture for several decades, the biology of Marchantia polymorpha subsp. ruderalis in nature has never been documented in detail in a single account. Here we synthesize routine field observations documented with hundreds of images of M. ruderalis colonies (or groups) showing sex differentiation over 3 years on two populations of M. ruderalis after major heathland fires in 2020. Initial post-fire establishment is from airborne spores rather than a spore bank but thereafter spread is via gemmae which have less exacting germination requirements. Young sporelings are highly gemmiferous but gemmae production becomes less frequent after sex organ formation. Over the course of a year there are up to three waves of carpocephalum production with the overwhelming majority of antheridiophores appearing 2-3 months ahead of the archegoniophores though no differences in growth rates were apparent between male and female thalli. Spermatozoids are produced almost continuously throughout the year, whilst sporophyte maturation is restricted to the summer months. Because of the asynchrony between antheridiophore and archegoniophore production a 1:1 sex ratio is only apparent over this period. The spring months see an excess of males with more females in the summer. An almost 100% fertilization rate, with fertilization distances of up to 19 m far exceeding those in all other bryophytes, is attributed to vast spermatozoid production for most of the year, dispersal on surface oil films between thalli and highly effective intra-thallus spermatozoid transport via the pegged-rhizoid water-conducting system. Archegoniophores do develop on female-only populations but have shorter stalks than those where fertilization has occurred. Eventual disappearance post fires is attributed to a fall in topsoil nutrient levels preventing new sporeling establishment and competition from Ceratodon purpureus and Polytrichum spp. A major drought in the summer of 2022 almost wiped out the heathland Marchantia populations but all the other bryophytes survived.

A mid-Cretaceous fungus, Philothysanus burmanicus gen. et sp. nov. (Ascomycota: Spheciophilaceae), on a thrip (Thysanoptera) in Burmese amber

Male and female thalli of a mid-Cretaceous fungus attached to a thrip (Thysanoptera) in Burmese amber are described as Philothysanus burmanicus gen. et sp. nov. in the family Spheciophilaceae (Ascomycota). Both spermatia and ascospores are present. Currently, Philothysanus burmanicus gen. et sp. nov., together with the previously described Spheciophilia adercia Poinar, represent the oldest known ectoparasitic fungi of insects and their age can be used as a reference point in future phylogenetic studies on the origin of fungi with this life style.

Body Weight Prediction of Thalli Sheep Reared in Southern Punjab Using Different Data Mining Algorithms

This study is conducted to predict the body weight (BW) for Thalli sheep of southern Punjab from different body measurements. In the BW prediction, several body measurements viz., withers height, body length, head length, head width, ear length, ear width, neck length, neck width, heart girth, rump length, rump width, tail length, barrel depth and sacral pelvic width are used as predictors. The data mining algorithms such as Chi-square Automatic Interaction Detector (CHAID), Exhaustive CHAID, Classification and Regression Tree (CART) and Artificial Neural Network (ANN) are used to predict the BW for a total of 85 female Thalli sheep. The data set is partitioned into training (80 %) and test (20 %) sets before the algorithms are used. The minimum number of parent (4) and child nodes (2) are set in order to ensure their predictive ability. The R2 % and RMSE values for CHAID, Exhaustive CHAID, ANN and CART algorithms are 67.38(1.003), 64.37(1.049), 61.45(1.093) and 59.02(1.125), respectively. The mostsignificant predictor is BL in the BW prediction of Thalli sheep. The heaviest BW average of 9.596 kg is obtained from the subgroup of those having BL > 25.000 inches. On behalf of the several goodness of fit criteria, we conclude that the CHAID algorithm performance is better in order to predict the BW of Thalli sheep and more suitable decision tree diagram visually. Also, the obtained CHAID results may help to determine body measurements positively associated with BW for developing better selection strategies with the scope of indirect selection criteria.

Body weight prediction using different data mining algorithms in Thalli sheep: A comparative study.

Background and Aim:The Thalli sheep are the main breed of sheep in Pakistan, and an effective method to predict their body weight (BW) using linear body measurements has not yet been determined. Therefore, this study aims to establish an algorithm with the best predictive capability, among the Chi-square automatic interaction detector (CHAID), exhaustive CHAID, artificial neural network, and classification and regression tree (CART) algorithms, in live BW prediction using selected body measurements in female Pakistani Thalli sheep.Materials and Methods:A total of 152 BW records, including nine continuous predictors (wither height, body length [BL], head length, rump length, tail length, head width, rump width, heart girth [HG], and barrel depth), were utilized. The coefficient of determination (R2), standard deviation ratio, root-mean-square error (RMSE), etc., were calculated for each algorithm.Results:The R2 (%) values ranged from 49.28 (CART) to 64.48 (CHAID). The lowest RMSE was found for CHAID (2.61), and the highest one for CART (3.12). The most significant predictors were the HG of live BW for all algorithms. The heaviest average BW (41.12 kg) was observed in the subgroup of those having a BL of >73.91 cm (Adjusted p=0.045).Conclusion:Among the algorithms, CHAID provided the most appropriate predictive capability in the prediction of live BW for female Thalli sheep. In general, the applied algorithms accurately predicted the BW of Thalli sheep, which can be very helpful in deciding on the standards, available drug doses, and required feed amount for animals.

Chemical Profiling of Volatile Components of the Gametophyte and Sporophyte Stages of the Hornwort Leiosporoceros dussii (Leiosporocerotaceae) From Panama by HS-SPME-GC-MS

We report for the first time the chemical profiling of volatile organic compounds (VOCs) of gametophyte and sporophyte life stages of Leiosporoceros dussii, from Panama by using headspace-solid phase microextraction-gas chromatography-mass spectrometry in order to assess distinguishing chemical markers between the male and female gametophytes, and sporophytes of this hornwort. A total of 27 VOCs were identified in L. dussii. Furthermore, the gametophyte and sporophyte showed clear differences in the type and amount of VOCs. The main constituents of L. dussii female thalli were menthacamphor (17.8%), hexanol (12.3%), and menthyl acetate (12.3%), while the major compounds of the male thalli were hexanol (25.3%), β-ionone (21.1%), benzeneacetaldehyde (17.6%), and β-cyclocitral (14.0%). The main VOCs of the sporophytes were hexanal (19.3%), β-cyclocitral (17.6%), 2-nonenal (15.8%), hexanol (12.5%), and β-ionone (10.2%). Unique compounds found in the female thalli were 3-pentanone, 3-octenol, nonanol, estragole, and menthyl acetate, and in the male thalli were methyl heptenone, nonanal, neoisomenthol, and bornyl acetate. Isomenthol, thymol, isomenthol acetate, and β-methylnaphthalene were only found in the sporophyte. The characteristic VOCs identified in L. dussii suggest a difference between the chemical constituents of L. dussii and other hornworts species. The presence of simple VOCs when compared with compounds previously characterized in another hornwort genera may support the distinct genetic nature of this species.

Do motile spermatozoids limit the effectiveness of sexual reproduction in bryophytes? Not in the liverwort Marchantia polymorpha

AbstractTo test the premise that fertilization distances in bryophytes are limited by spermatozoid motility, we measured the distances between over 80 000 male and female thalli of Marchantia polymorpha on heathland over 2 successive years after a major fire and recorded the incidence of sporophytes. The first comparative data on spermatozoid numbers per antheridium across bryophytes and pteridophytes were calculated from antheridial sizes and spermatid diameters and cross‐checked with the likely numbers produced by successive antheridial mitoses. Individual antheridia of Marchantia produce over 200 000 spermatozoids. Extrapolating from individual antheridia to the numbers of mature antheridia per antheridiophore and then to individual male plants, we calculated that a single flooding event on a male thallus with 10–12 antheridiophores will result in the release of over 50 million spermatozoids. Assuming radial dispersal in surface water films by lipids released from the dehiscing antheridia, spermatozoids can reach distances exceeding 20 m from the parent plants, in line with our finding of 100% fertilization in female plants of Marchantia up to 19 m from the nearest males, far beyond published fertilization distances in dioicous bryophytes. We attribute this to (i) much greater spermatozoid production and numbers in Marchantia than in other bryophytes and (ii) highly effective sperm transport both within the antheridiophores and archegoniophores via their overlapping scales and grooves in the stalks and between male and female thalli via surface water films. These features, coupled with the massive production of small spores, explain the success of Marchantia as the primary colonist of open habitats.

Optimal spawning conditions of Phyllospora comosa (Phaeophyceae, Fucales) for mariculture

The fucoid Phyllospora comosa has sparked interest from the industry as a potential commercial aquaculture species. However, information on the feasibility of culturing this species, including maximising spawning and fertilisation, remains limited. This study aimed to identify optimal conditions for spawning and early development of P. comosa under laboratory conditions. We tested spawning and germination success across lunar phase (new moon vs full moon), temperature (15 °C, 18 °C, 21 °C), light (35 μmol photons m−2 s−1 vs 0 μmol photons m−2 s−1) and exposure (desiccated vs submerged). Lunar cycles were compared over three consecutive months. Fifty fertile P. comosa male and female thalli were collected from Port Fairy, Victoria, Australia, every 2 weeks to coincide with full and new moon phases from February to April 2017. Spawning of eggs and sperm was achieved in all treatment combinations. However, there was no consistent effect of lunar phase, light, temperature or exposure, with high temporal variability amongst treatment groups. Percentage germination after 24 h in static culture varied between 35 and 90%, and overall embryo mortality was high (> 65%) after 7 days, but did not differ amongst spawning cue treatments. The high mortality observed at day 7 did not appear to be linked to insufficient egg or sperm densities nor excess sperm (polyspermy). Overall results indicate flexibility in spawning conditions which is advantageous for integration into aquaculture.

Occurrence of the endangered species Nitellopsis obtusa (Charales, Charophyceae) in western Japan and the genetic differences within and among Japanese populations

SummaryNitellopsis obtusa (Charales, Charophyceae) are widely distributed from Europe to Asia; however, this species has been recorded in only the five lakes in central Honshu in Japan. This species was thought to be extinct in Japan, but was rediscovered in limited areas of Lake Kawaguchi in central Honshu. More recently, we discovered more Japanese populations of N. obtusa in Lake Biwa in western Honshu, and it became clear that the species had a broader distribution in Japan than originally believed. In addition, although only male or female thalli have been collected at each lake, both male and female thalli were found from Lake Biwa. This is the first report of a potentially sexual population of N. obtusa in Japan. The DNA sequences of three chloroplast DNA markers, including both coding and non‐coding regions, were identical in all specimens from Lake Kawaguchi and Lake Nojiri (Central Honshu), and differed from those of Lake Biwa and German specimens. Although Japanese and German specimens were genetically similar, Japanese specimens displayed considerable genetic diversity according to locality.

Female-specific gene expression in dioecious liverwort Pellia endiviifolia is developmentally regulated and connected to archegonia production.

BackgroundIn flowering plants a number of genes have been identified which control the transition from a vegetative to generative phase of life cycle. In bryophytes representing basal lineage of land plants, there is little data regarding the mechanisms that control this transition. Two species from bryophytes - moss Physcomitrella patens and liverwort Marchantia polymorpha are under advanced molecular and genetic research. The goal of our study was to identify genes connected to female gametophyte development and archegonia production in the dioecious liverwort Pellia endiviifolia species B, which is representative of the most basal lineage of the simple thalloid liverworts.ResultsThe utility of the RDA-cDNA technique allowed us to identify three genes specifically expressed in the female individuals of P.endiviifolia: PenB_CYSP coding for cysteine protease, PenB_MT2 and PenB_MT3 coding for Mysterious Transcripts1 and 2 containing ORFs of 143 and 177 amino acid residues in length, respectively. The exon-intron structure of all three genes has been characterized and pre-mRNA processing was investigated. Interestingly, five mRNA isoforms are produced from the PenB_MT2 gene, which result from alternative splicing within the second and third exon. All observed splicing events take place within the 5′UTR and do not interfere with the coding sequence. All three genes are exclusively expressed in the female individuals, regardless of whether they were cultured in vitro or were collected from a natural habitat. Moreover we observed ten-fold increased transcripts level for all three genes in the archegonial tissue in comparison to the vegetative parts of the same female thalli grown in natural habitat suggesting their connection to archegonia development.ConclusionsWe have identified three genes which are specifically expressed in P.endiviifolia sp B female gametophytes. Moreover, their expression is connected to the female sex-organ differentiation and is developmentally regulated. The contribution of the identified genes may be crucial for successful liverwort sexual reproduction.

Vegetative and reproductive development of Mediterranean Gulsonia nodulosa (Ceramiales, Rhodophyta) and its genetic affinities

Rodríguez-Prieto C., Freshwater D.W. and Hommersand M.H. 2013. Vegetative and reproductive development of Mediterranean Gulsonia nodulosa (Ceramiales, Rhodophyta) and its genetic affinities. Phycologia 52: 357–367. DOI: 10.2216/13–132.1Gulsonia nodulosa was originally described as Crouania annulata by Berthold in 1882 and transferred to Gulsonia by Kylin in 1956 because its lateral indeterminate branches originated from the basal cells of whorled branchlets rather than being borne directly on the axis as a fourth branch. This study provided photographic evidence for the characters portrayed by other researchers and added new information concerning carposporophyte development. Each node bore four whorled branchlets that were usually up to five times trichotomously branched, terminated by one to four dichotomous branches and were formed in successive rows offset by 45°. Rhizoidal filaments were produced singly on basal cells of whorled branchlets and overlapped earlier-formed rhizoids while remaining undivided throughout their length. Plants were dioecious. Spermatangial parent cells arose as oppositely or quadraverticillately branched filaments on whorled branchlets, with each forming two to three spermatangia. Mature spermatangia were ovoid with a distal nucleus and a proximal vacuole, and released a single spermatium. Female thalli were procarpic and produced four-celled, L-shaped carpogonial branches proximally on young lateral branches of limited growth. After fertilization, the carpogonium cut off a terminal capping cell and a lateral connecting cell, whereas the supporting cell enlarged and divided transversely to produce a uninucleate auxiliary cell. The connecting cell fused with the auxiliary cell, its nucleus then dividing, with one of the derived nuclei entering the auxiliary cell and the other extruded in a residual cell that remained attached to the carpogonium. The diploidized auxiliary cell divided transversely into a diploid gonimoblast initial and a narrow bilobed foot cell in which the lobe nearest the carpogonium contained a diploid nucleus and the distal lobe received the original haploid nucleus, which usually divided into two nuclei. The first gonimolobe was produced laterally toward the carpogonium, followed by a second gonimolobe from the opposite side. A third gonimolobe sometimes formed midway between the first two. Involucral filaments surrounded the mature gonimolobes. Analyses of DNA sequences for two nuclear-encoded and two plastid-encoded genes indicated that G. nodulosa is more closely related to Ptilocladia and Euptilocladia species than to Crouania, and support hypothesized relationships of Crouanieae genera on the basis of morphological characters.

Transfer of the red alga Gelidium zollingeri Sonder (Gelidiales) to Yonagunia (Halymeniales) based on morphological and molecular evidence

Boo G.H, Park J.K., Gerung G.S. and Boo S.M. 2013. Transfer of the red alga Gelidium zollingeri Sonder (Gelidiales) to Yonagunia (Halymeniales) based on morphological and molecular evidence. Phycologia 52: 279–287. DOI: 10.2216/12–092.1An examination of the type specimen of Gelidium zollingeri Sonder showed that it was incorrectly placed in Gelidium. To determine the appropriate taxonomic position, we undertook a detailed morphological examination of the holotype (National Herbarium of Victoria, Australia) as well as fresh materials collected from Sempu, the type locality, and a surrounding location Kondang Merak in Malang city, East Jawa, Indonesia. In our collections we found tetrasporangia and carposporophytes on female thalli. The vegetative and reproductive structures clearly placed it in the Halymeniales. Four sequences of rbcL and cox1, two each from Sempu and Kondang Merak, were identical. Our analysis of rbcL sequences showed that G. zollingeri formed a monophyletic clade with the two known Yonagunia species, Y. formosana and Y. tenuifolia. Consequently, we proposed the new combination, Yonagunia zollingeri, based on Gelidium zollingeri. Yonagunia zollingeri was characterized by a cartilaginous, flattened thallus that was subcostate in lower parts, with cystocarpic leaflets that arose on terminal branchlets and round to heart-shaped tetrasporangial leaflets. Yonagunia is now known to occur in Indonesia, Japan (Okinawa), Malaysia, Taiwan, and Vietnam.

PURIFICATION OF A SEX-SPECIFIC LECTIN INVOLVED IN GAMETE BINDING OF AGLAOTHAMNION CALLOPHYLLIDICOLA (RHODOPHYTA)(1).

Egg and sperm binding and correct recognition is the first stage for successful fertilization. In red algae, spermatial attachment to female trichogynes is mediated by a specific binding between the lectin(s) distributed on the surface of trichogyne and the complementary carbohydrates on the spermatial surface. A female-specific lectin was isolated from Aglaothamnion callophyllidicola by agarose-bound fetuin affinity chromatography. Two proteins, 50 and 14 kDa, eluted from the fetuin column were separated using a native-polyacrylamide gel electrophoresis method and subjected to a gamete binding assay. The 50 kDa protein, which blocked spermatial binding to female trichogynes, was used for further analysis. Internal amino acid sequence of the 50 kDa protein was analyzed using matrix-assisted laser desorption/ionization-mass spectrometry and degenerated primers were designed based on the information. A full-length cDNA encoding the lectin was obtained using rapid amplification of cDNA ends polymerase chain reaction (PCR). The cDNA was 1552 bp in length and coded for a protein of 450 amino acids with a deduced molecular mass of 50.7 kDa, which agreed well with the protein data. Real-time PCR analysis showed that this protein was up-regulated about 10-fold in female thalli. As the protein was novel and showed no significant homology to any known proteins, it was designated Rhodobindin.

Laboulbeniales on Semiaquatic Heteroptera. A New Species of Triceromyces (Ascomycota, Laboulbeniales) on Microvelia (Heteroptera, Veliidae) from Spain

A new species of fungal genus Triceromyces (Laboulbeniales) is described: Triceromyces benjaminii. The description is based on several thalli found on the insect host Microvelia pygmaea (Heteroptera, Veliidae), collected in two localities from SE Spain. Characteristics of male and female thalli of this dioecious species are discussed and compared with other dioecious taxa. The characteristics of male thalli require some adjustment in generic limits. This is the first species of Triceromyces known to parasitize a species of Microvelia, a semiaquatic heteropteran genus. The new species is described and illustrated with line drawings and photographs. A table collates information on synonymy, hosts, geographical distribution, and salient references pertinent to taxa of Laboulbeniales parasitic on semiaquatic Heteroptera.

UV-absorbing compounds in Porphyra haitanensis (Rhodophyta) with special reference to effects of desiccation

The intertidal red alga Porphyra haitanensis Chang et Zheng is episodically desiccated and exposed to high levels of solar radiation at low tide during emersion. However, little has been documented on the relationship between the stresses during desiccation and related chemical compounds. We found that P. haitanensis thalli, when desiccated under indoor (artificial radiation) or outdoor (solar radiation) conditions, with or without UV radiation (UVR: 280–400 nm), contained significantly higher concentrations of UV-absorbing compounds (peak at 336 nm) than those maintained submerged (without desiccation). Solar UVR had no effect on the content of UV-absorbing compounds. Even though the concentration of these compounds decreased with time in all treatments, a slower decrease was observed in the desiccated samples. The samples with higher levels of UV-absorbing compounds showed higher photochemical efficiency of photosystem II (PS II) during the exposure or subsequent recovering process than samples with low concentration of UV-absorbing compounds, reflecting their protective role. The concentration of these compounds varied in different parts of the thallus, with the middle and marginal parts containing 60–80% more UV-absorbing compounds than the basal parts in both female and male plants. In addition, the marginal parts of male thalli contained more UV-absorbing compounds than the corresponding parts of female thalli. Our data suggest that desiccation plays a key role in this alga to maintain high concentration of UV-absorbing compounds, and that this might provide a beneficial advantage to compete in the intertidal zone where the organism is normally exposed to high levels of UVR.

The UV-absorbing compounds in gametophytic blades of Porphyra haitanensis and the effect on formation of sporangial branchlets of conchocelis

Endogenous levels of UVAC in different parts of matured gametophytic blades of Porphyra haitanensis and the effect of exogenous UVAC on sporangial branchlet formation are studied. The UVAC value in vegetative (36. 78 mg/g) and reproductive (29.25 mg/g) parts of female thallus is higher than their counterparts in male thallus (34.68 mg/g and 20.46 mg/g). The UVAC value of reproductive parts is higher than vegetative parts of same sexual thallus. The optimal UVAC concentration for sporangial branchlet formation is 0.1 mg/g.

Vegetative and reproductive morphology of the type species of Gloiocladia, G. furcata (Faucheaceae, Rhodophyta)

N. Sánchez and C. Rodríguez-Prieto. 2005. Vegetative and reproductive morphology of the type species of Gloiocladia, G. furcata (Faucheaceae, Rhodophyta). Phycologia 44: 222–233.The type species of Gloiocladia, G. furcata, is described in detail, and its characters are compared with those of other species currently accepted in Gloiocladia. The presence of a subcortex of ovoid, angular or stellate cells, connected by secondary pit connections to form a network parallel to the thallus surface, is confirmed. Female reproductive structures and postfertilization stages are described for the first time. Plants are procarpic, with the 3-celled carpogonial branch and two-celled auxiliary cell branch borne on a cortical cell that acts as supporting cell. The auxiliary cell contains a large proteinaceous inclusion. After fertilisation cells of the carpogonial branch fuse and connect to the auxiliary cell. The auxiliary cell divides into a primary gonimoblast cell that contains the proteinaceous inclusion and a lower auxiliary cell. A fusion cell between the auxiliary mother cell, the lower auxiliary cell and adjacent vegetative cells is formed. Gonimoblasts arising from the primary gonimoblast cell produce several erect projections bearing lobes of ovoid carposporangia. Basal nutritive cells are present, with erect persistent filaments (= tela arachnoidea) surrounding the fertilised procarp and the gonimoblast. Ostiolate cystocarps, with or without horns, arise on branch margins. Spermatangia remain unknown. Tetrasporangia are grouped in slightly raised nemathecia. In the family Faucheaceae, the presence of a subcortex in all individuals and the presence of basal nutritive tissue with erect persistent filaments in fertile female thalli are confirmed to be important taxonomic characters. These observations support the proposal of Norris (1991) to include Gloioderma in Gloiocladia but do not clarify the relationship between Gloiocladia and Fauchea.

동해안 고유종 긴잎돌김(Porphyra pseudolinearis)의 생태학적 연구

동해안 고유종인 긴잎돌김의 발생과 성숙, 생활사 등 생태에 관한 연구가 시행되었다. 긴잎돌김은 10월 초순에 발생하여 11월 말경에 성성숙이 시작되어 수정에 의해 과포자낭이 형성되고 과포자가 방출되었다. 3월 말경에 엽체가 소멸되었으며 이후 사상체, 각포자기를 거쳐 10월에 엽체가 발아하였다. 긴잎돌김의 특징으로 엽체는 피침형, 모근은 심장형이 대다수를 차지하였으며 거치상돌기가 없고 유성세대과정을 가지며 선명한 과포자낭무늬를 가진다. 암ㆍ수배우체에 있어 엽체와 엽폭비율은 성성숙기인 12월에 각각 5.6∼7.4 및 4.9∼7.3이였다. 1월에는 3.3∼4.8, 4.2∼4.8이였다. 개체수 변화는 10월 초순에 방형구(30<TEX>${\times}$</TEX>30 cm)내에 평균 5개체, 12월에는 238개체, 3월 중순에 15개체로 변화되었다. 성 분화가 시작되는 12월 초순에 암ㆍ수배우체 및 영양세포의 비율은 각각 31%, 47%, 22%였으며 완전 성숙된 12월 중순은 암ㆍ수배우체만 69.4% 및 30.6%였다. Growth and sexual differentiation of the seaweed Porphyra pseudolinearis Ueda have been investigated monthly in the intertidal zone of the East Sea, Korea. Young blades of P. pseudolinearis appeared at the beginning of October. Carp os pores were released at the end of November immediately after carposporangia formation. Then the thalli of P. pseudolinearis were extinguished at the end of March. Young thalli were budded through the stages of conchocelis and conchospore. Thalli showed lanceolate type in shape, cordate type in holdfast, absence of microscopic spinulate process and sexual generation. Ratios of length to width in female thalli ranged from 5.6 to 7.4 at the maturation in December and slightly decreased 3.3 to 4.8 in January and 4.9 to 7.3 in December while the ratios of male thalli ranged from 4.2 to 4.8 in January. On October 12, average five individuals were obsered in a quadrate (30 cm <TEX>${\times}$</TEX> 30 cm), 238<TEX>$\pm$</TEX>18 individuals for the maturation stage in December and then it was reduced to 150 individuals in February and 15 individuals in March. Average sex ratios for female, male and vegetative thalli were 31.3% 46.9% and 21.9% respectively in early December, the beginning time of sex maturation. The sex ratio of female and male thalli in December 17, changed to 69.4%, 30.6% respectively.

동해안 긴잎돌김(Porphyra pseudolinearis)의 성성숙기 특성

The seaweed Porphyra pseudolinearis as a dominant species grows at upper of the intertidal zone of the East Sea from October to March. Vegetative cells have not matured during October when observed with naked eye and microscope. In the middle of November, although it didn`t distingush between female and male gametophytes by eye, it showed antheridium and carpogonium when observed vertical section under microscope. From early December, It could be distinguished female and male gametophytes clearly. From Feburary it showed shorted length of thalli by release of spermatangia and carposporangia as maturation. At early March, the colar has been decaeded and side of thalli has been melted, completed of release of spermatia. At the end of December, the average length and width of female thalli were 149.9±5.6mm and 22.2±2.3mm, respectively. The length and width of male thalli were 149.9±9.4mm and 20.7±1.8mm. At the end of January, the average length and width of female thalli were 94.6±6.4mm and 29.1mm±5.1, respcetively. The length and width of male thalli were 107.8±7.3mm and 25.9±0.9mm. From this period lengths of female and male thalli have already been shortned by the release of spermatia and carpogonia.

The reproductive development of the red alga Actinotrichia fragilis (Galaxauraceae, Nemaliales)

The reproductive structures in Actinotrichia fragilis (Forsskål) Børgesen are described, including the first report of the structure and development of the carpogonial branch and cystocarp for the genus. Tetrasporangia usually arise in a terminal position on assimilatory filaments; occasionally they are formed laterally and in a secund manner. In male thalli, conceptacles are initiated from the apical pit of a thallus branch. Filaments bearing spermatangia issue from the inner face of the conceptacle wall. In female thalli, a carpogonial branch consists of a carpogonium, hypogynous cell and basal cell. Carpogonial branches may arise in two ways, either replacing a vegetative branch or rarely as a third branch between vegetative dichotomous branches. Before fertilization, the hypogynous cell divides to produce four cells. Subsequently, the basal cell produces branched filaments that eventually form the pericarp, which envelops the carpogonial branch and developing gonimoblast. After fertilization, the carpogonium divides transversely into two cells. The upper progeny cell retains its cytoplasmic connection to the trichogyne. The lower cell produces a lateral gonimoblast initial. Primary gonimoblast filaments form a compact pseudoparenchymatous mass at the base of the carposporophyte. Carposporangia are produced singly from the tips of the secondary gonimoblast filaments, which develop from the primary gonimoblast mass. Many simple or little-branched sterile paraphyses issue from the inner face of the pericarp and grow into the cavity. A comparison of the reproductive structures of Actinotrichia with those of the other genera of the Galaxauraceae suggests that the genus is closely related to Tricleocarpa Huisman et Borowitzka and Galaxaura Lamouroux.

The reproductive development of the red alga Actinotrichia fragilis (Galaxauraceae, Nemaliales)

The reproductive structures in Actinotrichia fragilis (Forsskal) Borgesen are described, including the first report of the structure and development of the carpogonial branch and cystocarp for the genus. Tetrasporangia usually arise in a terminal position on assimilatory filaments; occasionally they are formed laterally and in a secund manner. In male thalli, conceptacles are initiated from the apical pit of a thallus branch. Filaments bearing spermatangia issue from the inner face of the conceptacle wall. In female thalli, a carpogonial branch consists of a carpogonium, hypogynous cell and basal cell. Carpogonial branches may arise in two ways, either replacing a vegetative branch or rarely as a third branch between vegetative dichotomous branches. Before fertilization, the hypogynous cell divides to produce four cells. Subsequently, the basal cell produces branched filaments that eventually form the pericarp, which envelops the carpogonial branch and developing gonimoblast. After fertilization, the carp...