Mating behaviour of Heterozius rotundifrons (Crustacea : Brachyura : Belliidae): is it a hard or soft shell mater?

2005 ◽  
Vol 56 (8) ◽  
pp. 1107 ◽  
Author(s):  
G. A. Thompson ◽  
C. L. McLay
Keyword(s):  
New Zealand ◽  
Intertidal Zone ◽  
Mating Behaviour ◽  
Field Studies ◽  
Early Spring ◽  
Operational Sex Ratio ◽  
Soft Shell ◽  
Males And Females ◽  
Reproductive Characters ◽  
Water Borne

The Belliidae are a small family of crabs whose relationships with other families are enigmatic and whose composition is controversial. It is by no means certain whether their genera form a monophyletic group. One member of this family is Heterozius rotundifrons, a New Zealand endemic crab that lives in the intertidal zone, sheltering under rocks. In the present study the mating behaviour of this species was examined under laboratory conditions. Mating and moulting are closely linked because H. rotundifrons females only mate immediately after moulting. Females remain attractive to males for almost 3 days. A female-derived water-borne pheromone seems to be the basis of this attraction. Prior to moulting males guard females for up to 5 days. During the female moult some males were observed to assist the female. During copulation both males and females exhibited an unusual limb quivering behaviour and afterwards males guarded the females for 10.5 h, which was extended to 37 h when other males were present. Field studies showed that females moulted during early spring over a period of 1 month. Throughout the year very few females moulted, suggesting that there may be intense competition for mates during the early spring. At all times the operational sex ratio was biased in favour of males. In terms of the evolution of reproductive characters among the Belliidae, Atelecyclidae, Cheiragonidae and Corystidae, H. rotundifrons occupies an intermediate position between the ancestral condition and that seen in Corystes cassivelaunus.

Reproduction of paua, Haliotis iris Gmelin 1791 (Mollusca:Gastropoda), in north-eastern New Zealand

1995 ◽  
Vol 46 (3) ◽  
pp. 617 ◽  
Author(s):  
SH Hooker ◽  
RG Creese
Keyword(s):  
New Zealand ◽  
Gonad Index ◽  
Sharp Decrease ◽  
Late Summer ◽  
Early Spring ◽  
Reproductive Pattern ◽  
Marine Gastropods ◽  
North Eastern ◽  
Males And Females ◽  
Autumn And Winter

An examination of the reproductive condition of a population of paua, H. iris, at Leigh in north-eastern New Zealand during 1986-87 revealed a long breeding season extending from late summer through autumn and winter and into early spring. Within this period, a sharp decrease of over 60% in the gonad index for both males and females indicated major spawning events in July and October. A smaller decrease in the gonad index in March suggested a third, minor spawning. These spawning events were confirmed by regular examination of histological sections of gonadal material. This breeding pattern is different from that previously described for southern localities in New Zealand, where spawning activity is limited to a four-month period from late summer into autumn. Paua in this northern population had a sex ratio slightly biased towards males (1 female to every 1.3 males) and achieved reproductive maturity between the sizes of 48 and 60 mm shell length. These features are also different from those described for southern populations of H. iris. These findings highlight the need to take regional differences in reproductive pattern into account when describing the population dynamics of marine gastropods.

EVALUATION OF CLOVERS ON SANDY COASTAL SOIL

1977 ◽  
pp. 130-138 ◽  
Author(s):  
W.M. Williams ◽  
L.B. Anderson ◽  
B.M. Cooper
Keyword(s):  
New Zealand ◽  
Drought Stress ◽  
Sandy Soil ◽  
White Clover ◽  
Plant Material ◽  
Red Clover ◽  
Early Spring ◽  
Commercial Cultivars ◽  
Mediterranean Origin ◽  
Winter Annual

In evaluations of clover performances on summer-dry Himatangi sandy soil, it was found that none could match lucerne over summer. Emphasis was therefore placed on production in autumn-winter- early spring when lucerne growth was slow. Evaluations of some winter annual clover species suggested that Trifolium spumosum, T. pallidum, T. resupinatum, and T. vesiculosum would justify further investigation, along with T. subterraneum which is already used in pastures on this soil type. Among the perennial clover species, Kenya white clover (7'. semipilosum) showed outstanding recovery from drought and was the only species to produce significantly in autumn. However, it failed to grow in winter-early spring. Within red clover, materials of New Zealand x Moroccan origin substantially outproduced the commercial cultivars. Within white clover, material from Israel, Italy and Lebanon, as well as progeny of a selected New Zealand plant, showed more rapid recovery from drought stress and subsequently better winter growth than New Zealand commercial material ('Grasslands Huia'). The wider use of plant material of Mediterranean origin and of plants collected in New Zealand dryland pastures is advocated in development of clover cultivars for New Zealand dryland situations.

Postemergence Control of Italian Ryegrass in Hazelnut Orchards

2021 ◽  
pp. 1-22
Author(s):  
Marcelo L. Moretti
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Studies ◽  
Early Spring ◽  
Italian Ryegrass ◽  
Specific Response ◽  
Record Keeping ◽  
Effective Option ◽  
Contrast Analysis ◽  
Herbicide Use

Abstract Italian ryegrass has become a problematic weed in hazelnut orchards of Oregon because of the presence of herbicide-resistant populations. Resistant and multiple-resistant Italian ryegrass populations are now the predominant biotypes in Oregon; there is no information on which herbicides effectively control Italian ryegrass in hazelnut orchards. Six field studies were conducted in commercial orchards to evaluate Italian ryegrass control with POST herbicides. Treatments included flazasulfuron, glufosinate, glyphosate, paraquat, rimsulfuron, and sethoxydim applied alone or in selected mixtures during early spring when plants were in the vegetative stage. Treatment efficacy was dependent on the experimental site. The observed range of weed control 28 d after treatment was 13 to 76 % for glyphosate, 1 to 72% for paraquat, 58 to 88% for glufosinate, 16 to 97 % for flazasulfuron, 8 to 94% for rimsulfuron, and 25 to 91% for sethoxydim. Herbicides in mixtures improved control of Italian ryegrass compared to single active ingredients based on contrast analysis. Herbicides in mixture increased control by 27% compared to glyphosate, 18% to rimsulfuron, 15% to flazasulfuron, 19% to sethoxydim, and 12% compared to glufosinate when averaged across all sites, but mixture not always improved ground coverage of biomass reduction. This complex site-specific response highlights the importance of record-keeping for efficient herbicide use. Glufosinate is an effective option to manage Italian ryegrass. However, the glufosinate-resistant biotypes documented in Oregon may jeopardize this practice. Non-chemical weed control options are needed for sustainable weed management in hazelnuts.

Mortierella polycephala. [Descriptions of Fungi and Bacteria].

1997 ◽  
Author(s):  
P. M. Kirk
Keyword(s):  
New Zealand ◽  
Geographical Distribution ◽  
Former Ussr ◽  
Water Borne

Abstract A description is provided for Mortierella polycephala. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: From soil. DISEASE: None as a primary pathogen of plants; encountered as a saprobe. GEOGRAPHICAL DISTRIBUTION: Belgium, China, France, Gibraltar, India, Japan, Netherlands, New Zealand, UK, Ukraine, former USSR. TRANSMISSION: Movement of soil, or water-borne dispersal of sporangiospores.

scholarly journals Effects of the MaxP (TM) endophyte in tall fescue on pasture production and composition, and the sheep grazing preference in a dryland environment

2007 ◽  
Vol 13 ◽  
pp. 259-262
Author(s):  
K.N. Tozer ◽  
S. Ates ◽  
N.R. Mapp ◽  
M.C. Smith ◽  
R.J. Lucas ◽  
...  
Keyword(s):  
New Zealand ◽  
Tall Fescue ◽  
Dry Matter ◽  
Early Spring ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
Pasture Production ◽  
Basal Diameter ◽  
Matter Production ◽  
Annual Grasses

Pasture growth, botanical composition and sheep grazing preference were measured over 20 months in tall fescue (cultivar Advance), without endophyte (Nil) or infected with AR542 (MaxPTM) endophyte, and clover pastures sown into a dryland soil, Canterbury, New Zealand. Pastures were rotationally grazed with sheep, with grazing preference for the two endophyte treatments measured in late autumn and early spring. Annual dry matter production from April 2004 to April 2005 was not significantly different between AR542 (6293 kg DM/ha) and Nil (5864 kg DM/ha) tall fescue. The number of tall fescue plants/m2 and their basal diameter was greater for AR542 (35 plants/m2, 7.5 cm diameter) than Nil endophyte tall fescue (28 plants/m2, 6.8 cm diameter). AR542 endophyte tall fescue pastures had fewer weeds, mainly annual grasses, than Nil endophyte pastures throughout the trial. Grazing preference, measured by the number of sheep grazing each plot, and decline in pasture height did not differ between Nil and AR542 tall fescue. Keywords: tall fescue, novel endophyte, AR542, botanical composition, weed, grazing preference

scholarly journals Sex identification in embryos and adults of Darwin’s finches

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0237687
Author(s):  
Mariya P. Dobreva ◽  
Joshua G. Lynton-Jenkins ◽  
Jaime A. Chaves ◽  
Masayoshi Tokita ◽  
Camille Bonneaud ◽  
...  
Keyword(s):  
Field Studies ◽  
Sexually Dimorphic ◽  
Genetic Studies ◽  
Darwin's Finches ◽  
Darwin’S Finches ◽  
Specific Morphology ◽  
Males And Females ◽  
Primer Sets ◽  
Dimorphic Species ◽  
Source Of Error

Darwin’s finches are an iconic example of adaptive radiation and evolution under natural selection. Comparative genetic studies using embryos of Darwin’s finches have shed light on the possible evolutionary processes underlying the speciation of this clade. Molecular identification of the sex of embryonic samples is important for such studies, where this information often cannot be inferred otherwise. We tested a fast and simple chicken embryo protocol to extract DNA from Darwin’s finch embryos. In addition, we applied minor modifications to two of the previously reported PCR primer sets for CHD1, a gene used for sexing adult passerine birds. The sex of all 29 tested embryos of six species of Darwin’s finches was determined successfully by PCR, using both primer sets. Next to embryos, hatchlings and fledglings are also impossible to distinguish visually. This extends to juveniles of sexually dimorphic species which are yet to moult in adult-like plumage and beak colouration. Furthermore, four species of Darwin’s finches are monomorphic, males and females looking alike. Therefore, sex assessment in the field can be a source of error, especially with respect to juveniles and mature monomorphic birds outside of the mating season. We caught 567 juveniles and adults belonging to six species of Darwin’s finches and only 44% had unambiguous sex-specific morphology. We sexed 363 birds by PCR: individuals sexed based on marginal sex specific morphological traits; and birds which were impossible to classify in the field. PCR revealed that for birds with marginal sex specific traits, sexing in the field produced a 13% error rate. This demonstrates that PCR based sexing can improve field studies on Darwin’s finches, especially when individuals with unclear sex-related morphology are involved. The protocols used here provide an easy and reliable way to sex Darwin’s finches throughout ontogeny, from embryos to adults.

scholarly journals ECONOMICS OF NITROGEN USE IN DAIRYING

1982 ◽  
pp. 70-75
Author(s):  
D.A.L. Buxton
Keyword(s):  
New Zealand ◽  
Research Work ◽  
Dairy Farms ◽  
Early Spring ◽  
The Other ◽  
Stocking Rate ◽  
Nitrogen Use

During the last 10 to 15 years, the use of fertiliser N at low rates on New Zealand dairy farms has become more popular. There are many ways in which fertiliser N can be used to increase pasture and milkfat production. Five of those options are analysed, viz. I. High rates of N. 2. Bridging a spring feed deficit. 3. Increasing stocking rate. 4. Earlier calving. 5. More cow condition. Research work is finding the best times and rates of application of N. The extra pasture produced must then be utilised to maximise milkfat responses. Trials have shown that the use of high rates of fertiliser N ( > 80 kg N/ha) is unlikely to be profitable on N.Z. dairy farms. N used to enable more cows to be wintered, and then milked in early spring, appears to be very profitable, due to better utilisation of later spring-autumn pasture growth. The other three options are also profitable, but the increase in total farm milkfat production is only 3 to 4%. The options need to be tested more thoroughly with models and grazing experiments.

scholarly journals Nocturnal mating behaviour and dynamic male investment of copulation time in the southern blue-ringed octopus, Hapalochlaena maculosa (Cephalopoda: Octopodidae)

Behaviour ◽  
2015 ◽  
Vol 152 (14) ◽  
pp. 1883-1910 ◽  
Author(s):  
Peter Morse ◽  
Kyall R. Zenger ◽  
Mark I. McCormick ◽  
Mark G. Meekan ◽  
Christine L. Huffard
Keyword(s):  
Mating Systems ◽  
Mating Behaviour ◽  
Female Size ◽  
Male Size ◽  
Male Preference ◽  
Video Footage ◽  
Mating History ◽  
Males And Females ◽  
Strategic Allocation ◽  
Do So

The southern blue-ringed octopus,Hapalochlaena maculosaHoyle (1883), is a nocturnal species that exhibits a mating system in which females hold sperm from multiple males over a one to two month breeding window before laying a single egg clutch. Contrary to most studied animal mating systems where anisogamy exists, gamete package production is limited for both males and females of this species (approx. 50 spermatophores/eggs). This presents an animal model for studying aspects of sperm competition and dynamic mate choice behaviours. The present study reports on the mating behaviour ofH. maculosaobserved under laboratory conditions using infrared closed-circuit television video footage. Rates of male copulation attempts increased with male size, while female receptivity to mating attempts increased with female size, resulting in larger animals of both sexes gaining more copulations and spending more time per day in copulation. There was some evidence of female preference of larger males, but no male preference of females based on measured morphological traits. Both sexes terminated copulations in equal frequencies but male-terminated copulations were significantly shorter in duration. Males were more likely to terminate copulation early with females they had previously mated with, however were less likely to do so if the female had recently mated with a different male. Among male-terminated copulations, males mated for longer with females that had previously mated with other males in the trial. Male–male mounts were as common as male–female mounts, suggesting that maleH. maculosaare not able to discriminate the sex of conspecifics. These findings suggest male strategic allocation of spermatophores based female mating history is an important factor influencing mating behaviours of this species.

Distinguishing ten sympatric species of fiddler crab (Decapoda: Ocypodidae) using a suite of phenotypic characteristics

Zootaxa ◽  
2021 ◽  
Vol 5026 (4) ◽  
pp. 480-506
Author(s):  
LAURA A. MICHIE ◽  
R. S. K. BARNES ◽  
PAUL F. CLARK ◽  
WAYNE A. BENNETT ◽  
SIMON M. CRAGG
Keyword(s):  
Fiddler Crab ◽  
Taxonomic Revision ◽  
Field Studies ◽  
Sympatric Species ◽  
Phenotypic Characteristics ◽  
Biogeographic Region ◽  
Males And Females ◽  
First Time ◽  
The Village ◽  
Major Cheliped

Ten species of fiddler crab are reported inhabiting the intertidal zone of a shore on Kaledupa Island, Indonesia. This is one of the highest recorded numbers of fiddler crab species living in sympatry, equating to over two-thirds of those known from the Wallacea biogeographic region and more than half of all those recorded from Indonesia. The descriptions to identify and distinguish these ten species are provided using a suite of characters e.g., carapace, major cheliped, male gonopods, gastric mills, life colouration in males and females, and notes on their ecology and distribution. Specimens were observed and collected in the Wakatobi National Park, near the village of Ambeua on Kaledupa island, Sulawesi Tenggara, Indonesia. Gastric mills are described for the first time for Gelasimus jocelynae, Paraleptuca crassipes, Tubuca coarctata, T. demani and T. dussumieri. A tabulation of anatomical features and colouration for all species in this study is provided as a support for field studies. It identifies features that support the recently proposed taxonomic revision of fiddler crabs by Shih et al. (2016).  

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