Commensalism of a Bivalve, Peregrinamor Ohshimai, With a Thalassinidean Burrowing Shrimp, Upogebia Major

1995 ◽  
Vol 75 (4) ◽  
pp. 941-947 ◽  
Author(s):  
Makoto Kato ◽  
Gyo Itani
Keyword(s):  
Shell Length ◽  
Suspended Matter ◽  
Carapace Length ◽  
Anterior Part ◽  
Living Organism ◽  
Ventral Side ◽  
Filter Feeding ◽  
Water Currents ◽  
Veliger Larva ◽  
The Seto Inland Sea

Ecological, behavioural and anatomical observations of a commensal bivalve, Peregrinamor ohshimai (Mollusca: Galeommatoidea), were carried out in a tidal mudflat in the Seto Inland Sea, Japan. The bivalve attached specifically to the longitudinal groove of the ventral side of the cephalothorax of thalassinidean burrowing shrimps, Upogebia major and Lf. narutensis (Crustacea: Decapoda), singly, dorso-ventrally and longitudinally, using its byssus, with its anterior part towards the head of the host. The mantle of the commensal bivalve has wide anterior (branchio-pedal) and narrow posterior (exhalant) apertures. In the living organism, the extended anterior edges of the mantle protrude from the shell and are inserted into the host's filtering basket, which is formed by the setal rows of the first two pairs of pereiopods and utilized for intercepting suspended matter. By beating its pleopods in a U-shaped burrow, the filter-feeding Upogebia shrimp creates water currents, which are also utilized by the commensal bivalve for filter-feeding. The shell length of the commensal bivalve was in proportion to the host's carapace length. This suggests that the veliger larva attaches to a young host and grows, thus maintaining the host-commensal morphological matching. The bivalve is a hermaphrodite and individuals of >8–5 mm in shell length were already producing eggs. Anatomical observations suggest that P. ohshimai is most closely related to the Montacutidae in Galeommatoidea.

scholarly journals A summary of further experimental researches on the etiology of endemic goitre. (Second series.)

1911 ◽  
Vol 83 (564) ◽  
pp. 335-337 ◽  
Keyword(s):  
Thyroid Gland ◽  
Suspended Matter ◽  
Royal Society ◽  
Intestinal Tract ◽  
Living Organism ◽  
Causal Factor ◽  
Endemic Goitre ◽  
Experimental Researches ◽  
Disease Present

The object of the research was to test by further experimentation on man the accuracy of the results communicated to the Royal Society on November 26, 1908. These results afforded evidence that goitre was due to a living organism of disease present in the water of goitrous localities, that the causal factor of the disease was destroyed by boiling, and that it inhabited, in all probability, the intestinal tract of man. I. Twenty-three individuals, of the average age of 22, consumed the suspended matter of goitre-producing water for periods of from 30 to 55 days. Of these, six showed an increase in size of the thyroid gland which persisted in a more or less well-marked manner up to the end of the experiments. Three others showed a thyroid hypertrophy of a transitory character.

Theoretical morphology of hinge and shell form in Bivalvia: geometric constraints derived from space conflict between umbones

Paleobiology ◽  
2000 ◽  
Vol 26 (4) ◽  
pp. 606-624 ◽  
Author(s):  
Takao Ubukata
Keyword(s):  
Computer Simulation ◽  
Anterior Part ◽  
Large Degree ◽  
Ventral Side ◽  
Mutual Interference ◽  
Geometric Constraints ◽  
Geometric Properties ◽  
Shell Form ◽  
Theoretical Morphology

Geometric properties of the shells of 123 species of extant Bivalvia were analyzed from the viewpoint of theoretical morphology. The effects of shell form and the structure of ligament on the interumbonal space and the maximum shell opening received particular attention. The results of computer simulation and morphospace analysis indicate that possessing both prosogyrous shell form and an extended hinge without the parivincular ligament tends to cause space conflict between umbones or dorsal shell margins of right and left valves. To a large degree, a prosogyrous shell form with a long parivincular ligament helps shell opening without umbonal conflict, if the shell is flat enough to avoid the mutual interference between dorsal shell margins of closed valves. Extension of the ligament and plunging of the anterior part of the coiling axis into the ventral side provide enough space along the dorsal shell margins in which a parivincular ligament and its substrata are developed.

Crab-eating in the diamondback terrapinMalaclemys terrapin: dealing with dangerous prey

1992 ◽  
Vol 72 (4) ◽  
pp. 835-848 ◽  
Author(s):  
John Davenport ◽  
Martha Spikes ◽  
Sarah M. Thornton ◽  
Bridget O. Kelly
Keyword(s):  
Shell Length ◽  
Smooth Surface ◽  
Carapace Length ◽  
Carapace Width ◽  
Shell Height ◽  
Diamondback Terrapins

Male diamondback terrapins,Malademys terrapin(190–240 g; 101–117 mm carapace length; 11–8 ±0–6 mm maximum jaw gape) selected small littorinids (<12 mm shell height) and mussels (<30 mm shell length) when offered prey of a range of sizes (at 26°C and 34‰. Jaw gape appeared to be the main constraint on feeding on molluscs. Responses to crabs were complex. Small crabs (10–25 mm carapace width) were eaten whole. Medium-sized crabs (30–50 mm carapace width) were ‘cropped’ (i.e.walking legs were eaten without killing the crabs). Large crabs (52–75 mm carapace width) were usually avoided, though terrapins sometimes took legs from pairs 3 or 4. Experiments with medium-sized crabs showed that diamondbacks evaluated crabs visually before attacking and preferred to eat crabs without chelipeds, rather than crabs with one or two chelipeds. Terrapins carried out attacks on medium-sized crabs from the side or rear and preferentially cropped leg pair 4 (the furthest from the chelipeds), even though leg pair 4 was significantly less valuable energetically than other leg pairs. Evidence is presented to show that cropping behaviour allows terrapins to exploit crabs which are too large to eat whole because of the constraints of jaw gape and the hard, smooth surface of the crab cephalothorax. Limb cropping is as energetically profitable as eating small crabs whole, but the threat posed by chelipeds causes terrapins to attack crab prey in the order small>medium>large.

scholarly journals Morphogenesis of the Ciliature During Sexual Process of Conjugation in the Ciliated Protist Euplotes raikovi

2021 ◽  
Vol 7 ◽  
Author(s):  
Usman Asghar ◽  
Yong Chi ◽  
Yunyi Gao ◽  
Borong Lu ◽  
Yaohan Jiang ◽  
...  
Keyword(s):  
De Novo ◽  
Anterior Part ◽  
Posterior Part ◽  
Marine Species ◽  
Ventral Side ◽  
Fragmentation Pattern ◽  
Morphogenetic Process ◽  
Stable Pattern ◽  
Sexual Process ◽  
Euplotes Raikovi

Morphogenesis is an important process that widely occurs in almost all the organisms, including the ciliated protists. Ciliates are a large group of single-celled eukaryotes that can reproduce asexually (e.g., binary fission) and perform sexual process (e.g., conjugation). Morphogenesis happens in both asexual reproduction and sexual process in ciliates and the reorganization during conjugation is more complex. However, studies of morphogenesis focusing on conjugation are very limited. Here we studied the morphogenetic process during conjugation in the marine species Euplotes raikovi Agamaliev, 1966. The results indicate that: (1) the ciliature in the ventral side reorganizes twice during sexual process, i.e., conjugational and postconjugational reorganization; (2) the adoral zone of membranelles (AZM) is generated de novo in a pouch beneath the cortex during both reorganizations, with the anterior part generated during the first reorganization, while the posterior part formed during the second reorganization; (3) the frontoventral-transverse (FVT) cirri anlagen are formed de novo in both processes with the fragmentation pattern of 2:2:3:3:2; (4) one left marginal cirrus is generated de novo during both reorganizations; and (5) the dorsal ciliature remains intact during the whole process, except that the two caudal cirri originate from the end of the right-most two dorsal kineties during both reorganizations. Comparisons of the morphogenetic process during conjugation demonstrate a considerably stable pattern within Euplotes while the patterns vary dramatically among different ciliate groups.

Feeding technique, critical size and size preference of Jasus edwardsii fed cultured and wild mussels

1998 ◽  
Vol 49 (2) ◽  
pp. 151 ◽  
Author(s):  
Philip J. James ◽  
Lennard J. Tong
Keyword(s):  
Shell Length ◽  
Carapace Length ◽  
Critical Size ◽  
Dry Weight ◽  
Shell Morphology ◽  
Strongly Correlated ◽  
Rock Lobster ◽  
Perna Canaliculus ◽  
Jasus Edwardsii ◽  
Innate Behaviour

This paper describes a technique used by juvenile red rock lobsters, Jasus edwardsii, 20–70 mm carapace length, to open and feed on live mussels. This technique appears to be an innate behaviour. The maximum or critical size (shell length) of cultured and wild Mytilus galloprovincialis, and cultured Perna canaliculus, which J. edwardsiiis capable of opening, is strongly correlated with lobster carapace length. Jasus edwardsii is capable of opening significantly larger cultured than wild M. galloprovincialis; this is a reflection of the differences in shell morphology between wild and cultured mussels, and the vulnerability of different shapes to the opening technique employed. In replacement experiments, the greatest numbers of mussels were eaten from the smallest mussel sizes (6–20 mm shell length), whereas the greatest amount of dry flesh weight was consumed from the middle mussel sizes (11–40 mm shell length) for all three mussel types. Dry-weight consumption was considered the most appropriate indicator of preference, the amount of mussel flesh consumed being more relevant to a rock lobster farmer than the numbers of mussels eaten. The preferred mussel size was approximately half the critical size. The application of these results to rock lobster farming is discussed.

scholarly journals Redescription of Larval Development in Cultured Pearl Oyster Pinctada maxima

2018 ◽  
Vol 23 (2) ◽  
pp. 109
Author(s):  
Jeane Siswitasari Mulyana ◽  
Achmad Farajallah ◽  
Yusli Wardiatno
Keyword(s):  
Developmental Stage ◽  
Larval Development ◽  
Shell Length ◽  
Shell Height ◽  
Pearl Oyster ◽  
Oyster Culture ◽  
Veliger Larva ◽  
Pinctada Maxima

Larval development plays a major role in efficient pearl culture. The cultured larvae will be later used for recipient and donor oysters in cultured pearl production. Larval developmental stage of silver lip pearl oyster Pinctada maxima has been reported by several studies. Those studies used female and male oyster parents directly taken from natural habitat.This study aimed to redescribe larval development of P. maxima from commercial pearl oyster culture farm in Indonesia. Larval development of this species whose parents are originated from selected groups in the pearl culture farm has not been reported yet, thus it is necessary to be described. This species undergoes specific larval developmental stage. The larvae were observed under microscope, and then the average shell length (SL) and shell height (SH) were measured. D-shaped veliger larva (77.4±0.3 µm SL; 65.4±1.1 µm SH) appeared 20 h after fertilization. Tenday-old larva (156.2±2.8 µm SL; 149.5±5.6 µm SH) had developed umbo region so it was called umbonal larva. Umbonal larva then developed further into plantigrade larva (411.3±9.8 µm SL; 380.5±6.9 µm SH) in 25 days after fertilization. Developmental stage and larval sizein P. maxima is similar with those observed in P. fucata and P. margaritifera. Keywords: growth, larva, plantigrade, shell, umbo, veliger

Fasciola gigantica: surface topography of the adult tegument

2001 ◽  
Vol 75 (1) ◽  
pp. 43-50 ◽  
Author(s):  
T. Dangprasert ◽  
W. Khawsuk ◽  
A. Meepool ◽  
C. Wanichanon ◽  
V. Viyanant ◽  
...  
Keyword(s):  
Anterior Part ◽  
Ventral Side ◽  
Ventral Surface ◽  
Dorsal Side ◽  
Fasciola Gigantica ◽  
The Body ◽  
Lateral Aspect ◽  
Tegumental Surface ◽  
Type 3

Adult Fasciola gigantica are leaf-shaped with tapered anterior and posterior ends and measure about 35 mm in length and 15 mm in width across the mid section. Under the scanning electron microscope its surface appears rough due to the presence of numerous spines and surface foldings. Both oral and ventral suckers have thick rims covered with transverse folds and appear spineless. On the anterior part of the ventral surface of the body, the spines are small and closely-spaced. Each spine has a serrated edge with 16 to 20 sharp points, and measures about 20 μm in width and 30 μm in height. In the mid-region the spines increase in size (up to 54 μm in width and 58 μm in height) and number, especially towards the lateral aspect of the body. Towards the posterior end the spines progressively decrease in both size and number. The tegumental surface between the spines appears highly corrugated with transverse folds alternating with grooves. At higher magnifications the surface of each fold is further increased with a meshwork of small ridges separated by variable-sized pits or slits. There are three types of sensory papillae on the surface. Types 1 and 2 are bulbous, measuring 4–6 μm in diameter at the base with nipple-like tips, and the type 2 also have short cilia. Type 3 papillae are also bulbous and of similar size but with a smooth surface. These sensory papillae usually occur in clusters, each having between 2 and 15 units depending on the region of the body. Clusters of papillae on the lateral aspect (usually types 1 and 2) and around the suckers (type 3) tend to be more numerous and larger in size. The dorsal side of the body exhibits similar surface features, but the spines and papillae appear less numerous and are smaller. Corrugation and invaginations of the surface are also less extensive than on the ventral side of the body.

Slip-resistant silver-feet: shell form and mode of life in lower Pleistocene Argyropeza from Fiji

1986 ◽  
Vol 60 (5) ◽  
pp. 1066-1074 ◽  
Author(s):  
Alan J. Kohn
Keyword(s):  
Grain Size ◽  
Shell Length ◽  
Direct Relationship ◽  
Ventral Side ◽  
Drilling Predation ◽  
Length Range ◽  
Lower Pleistocene ◽  
Mode Of Life ◽  
Enhance Efficiency ◽  
Lines Of Evidence

Asymmetric sculpture in the form of tubercles or ridges on the shells of large (mean shell length ~60 mm) turritelliform gastropods has previously been shown to enhance efficiency of the shell as a penetration anchor in burrowing through coarse sediment. The small (<8 mm) turritelliform shells of all species of Argyropeza (Family Cerithiidae) have both of these ratchetlike sculptural features. Four lines of evidence from Lower Pleistocene A. divina and A. schepmaniana from Fiji support the interpretation that they help resist back-slippage: cross-orientation, frictional asymmetry, allometric shallowing, and allometric densing of sculptural elements. In addition, excellent state of preservation including protoconch sculpture, near coplanarity of aperture and ventral side of shell, and susceptibility to drilling predation by naticids support the conclusion that these gastropods burrowed in the sediment that formed the siltstone in which they are now preserved. A direct relationship is proposed between height of ratchet sculpture on turritelliform gastropod shells of approximate length range 5–100 mm and the grain size of sediments they inhabit ranging from silts to coarse sands.

Three new and a known species of Tylencholaimoidea (Nematoda: Dorylaimida) from Singapore

Zootaxa ◽  
2010 ◽  
Vol 2505 (1) ◽  
pp. 51 ◽  
Author(s):  
WASIM AHMAD ◽  
M. BANIYAMUDDIN
Keyword(s):  
Anterior Part ◽  
Ventral Side ◽  
Cylindrical Part ◽  
Genital System ◽  
Muscular Structure ◽  
Female Genital System ◽  
Basal Bulb ◽  
First Time ◽  
Labial Disc ◽  
Female Genital

Three new and a known species of soil-inhabiting nematodes belonging to the superfamily Tylencholaimoidea Filipjev, 1934 are described and illustrated from Singapore. Tantunema enigmatum n. sp. is characterised by having 0.33–0.41 mm long body; angular, distinctly offset lip region; well developed circumoral sclerotization; odontostyle slender with aperture about one-fourth of its length; simple rod-like odontophore; anterior part of pharynx slender, weakly muscular, expanding abruptly into a cylindroid basal bulb, constriction present between two parts of pharynx; expanded portion divisible into a short conical, less muscular anterior part and a posterior muscular cylindrical part with thickened inner lining; lumen of the posterior one-third of expanded portion distinctly widened and thickened; mono-opisthodelphic female genital system and short hemispheroid tail. Dorella shamimi n. sp. is characterised by having 0.58–0.62 mm long body; continuous lip region with indistinct labial papillae; labial disc absent; 10–10.5 µm long odontostyle with a large pad-like muscular structure attached on ventral side of posterior half of its length extending to the anterior part of the odontophore; odontophore asymmetrical with round, transparent, knob-like thickening; pharynx with a short terminal oval bulb; mono-prodelphic female genital system with a short post-uterine sac; short conoid tail, with rounded terminus, and males with 18–18.5 µm long, simple arcuate spicules and a single ventromedian supplement. Tylencholaimus singaporensis n. sp. is characterized by having 0.35–0.47 mm long body; distinctly offset, cap-like lip region, 4.5–5.5 µm long, slender odontostyle, simple rod-like odontophore with small but distinct basal knobs, pharyngeal expansion abrupt, mono-prodelphic genital system with no post-uterine sac, and short hemispheroid tail with distinct terminal caudal pore. Tylencholaimus intermedius Peña-Santiago & Coomans, 1996 is reported for the first time from Singapore.

scholarly journals Life in the Current: Anatomy and Morphology of Utricularia neottioides

2020 ◽  
Vol 21 (12) ◽  
pp. 4474 ◽  
Author(s):  
Bartosz J. Płachno ◽  
Lubomír Adamec ◽  
Piotr Świątek ◽  
Małgorzata Kapusta ◽  
Vitor F. O. Miranda
Keyword(s):  
Vegetative Reproduction ◽  
Ventral Side ◽  
Carnivorous Plant ◽  
South American ◽  
Water Currents ◽  
Anchor System ◽  
Asymmetric Structures ◽  
Transmission Electron ◽  
Organ Systems ◽  
Standing Waters

Rheophytism is extremely rare in the Utricularia genus (there are four strictly rheophytic species out of a total of about 260). Utricularia neottioides is an aquatic rheophytic species exclusively growing attached to bedrocks in the South American streams. Utricularia neottioides was considered to be trap-free by some authors, suggesting that it had given up carnivory due to its specific habitat. Our aim was to compare the anatomy of rheophytic U. neottioides with an aquatic Utricularia species with a typical linear monomorphic shoot from the section Utricularia, U. reflexa, which grows in standing or very slowly streaming African waters. Additionally, we compared the immunodetection of cell wall components of both species. Light microscopy, histochemistry, scanning, and transmission electron microscopy were used to address our aims. In U. neottioides, two organ systems can be distinguished: organs (stolons, inflorescence stalk) which possess sclerenchyma and are thus resistant to water currents, and organs without sclerenchyma (leaf-like shoots), which are submissive to the water streaming/movement. Due to life in the turbulent habitat, U. neottioides evolved specific characters including an anchor system with stolons, which have asymmetric structures, sclerenchyma and they form adhesive trichomes on the ventral side. This anchor stolon system performs additional multiple functions including photosynthesis, nutrient storage, vegetative reproduction. In contrast with typical aquatic Utricularia species from the section Utricularia growing in standing waters, U. neottioides stems have a well-developed sclerenchyma system lacking large gas spaces. Plants produce numerous traps, so they should still be treated as a fully carnivorous plant.

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