Memoirs: The Development of the Serpiilid Pomatoeeros Triqueter L

1. The larvae of Pomatoceros triqueter L. were obtained by artificial fertilization and reared through metamorphosis and for several months afterwards. Larval development took three weeks in summer, and about the same time in winter when the temperature was maintained at 65° F. 2. The eggs are small and give rise to typical trochosphere larvae with well-developed prototroch, metatroch, neurotroch, and feeding cilia, a spacious blastocoelic body-cavity and paired protonephridia. A head-vesicle and a conspicuous anal vesicle are also present. The right eye develops before the left. The larva is very active and grows rapidly at the expense of collected food material. 3. Three setigerous segments arise simultaneously; a fourth is added prior to metamorphosis. The lateral collar-folds develop in two capacious pockets which arise by invagination of the body-wall behind the metatroch, the ventral collar-fold by outgrowth of the ventral body-wall. The rudiments of the thoracic membrane appear above the lateral collar-folds. 4. Metamorphosis commences with the shrinkage of the locomotor apparatus, which leads to the exposure of the lateral collar-folds. The larva settles to the bottom and creeps about on its ventral surface by means of the neurotroch. The branchial crown arises as tripartite outgrowths on the sides of the head. The remaining tissues of the head, apart from the cerebral ganglion and eyes, are gradually resorbed. No tissue is thrown off. 5. The neurotroch gradually disappears and is replaced by cilia on the dorsal surface. The worm begins to secrete a calcareous tube. The resorption of the head is completed and the mouth assumes a terminal position surrounded by the branchial crown. 6. A fourth pair of filaments is added to the branchial crown. The dorsal pair of filaments develops into 'palps'. The third filament on the left side is modified as the operculum; the remaining filaments develop pinnules. 7. Further segments are added to the trunk. Those first added are of the thoracic type from the beginning. The eighth and succeeding setigers are of the abdominal type. The thoracic membrane gradually extends backwards to the posterior end of the thorax. 8. The thoracic nephridia arise as a single pair of cells which give rise to the dorsal unpaired duct by outgrowth. 9. The influence of the egg on the course of development is discussed. It is suggested: (a) that the small size of the egg is responsible for the active habits and protracted pelagic life of the larva; (b) that the mode of development of the collar is significant in that interference with the locomotor and feeding apparatus is thereby avoided; (c) that the general shrinkage which occurs at metamorphosis is related to a suspension of feeding activity in the period between the degeneration of the larval and the establishment of the adult feeding apparatus. 10. The development of Pomatoceros is compared with that of the Serpulid Psygmobranchus and the Sabeilid Branchiomma.

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Multiple records and polymorphism of Parastichopus regalis (Cuvier, 1817) (Echinodermata: Holothuroidea: Stichopodidae) along the Algerian coast

Zootaxa ◽

10.11646/zootaxa.5032.4.5 ◽

2021 ◽

Vol 5032 (4) ◽

pp. 549-562

Author(s):

IHCENE KHODJA ◽

KARIM MEZALI ◽

AHMED S. THANDAR

Keyword(s):

Statistical Analysis ◽

Mediterranean Sea ◽

Endemic Species ◽

Body Wall ◽

Dorsal Surface ◽

The Body ◽

The Other ◽

Disk Diameter ◽

The Family ◽

Algerian Coast

The family Stichopodidae is represented in the Mediterranean Sea by the genus Parastichopus which includes two non-endemic species; Parastichopus tremulus (Gunnerus, 1767) and Parastichopus regalis (Cuvier, 1817). On the Algerian coast (southwestern Mediterranean Sea), two morphotypes of P. regalis were observed, one with dark spots on the dorsal surface and the other non-spotted. In total, 65 individuals of P. regalis were recorded from 22 stations along the Algerian coast during an oceanographic campaign. Twelve individuals (6 of each morphotype) were used for a comparative study of the morphological (including endoskeletal) characteristics. Table ossicles, the only ossicles of the body wall of the two morphotypes of P. regalis, are here compared with regard to the disk diameter of the tables and the total area of the surface of the disc. Statistical analysis did not show any significant differences between the spotted and the non-spotted morphotypes.

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Candidate ionotropic taste receptors in the Drosophila larva

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1503292112 ◽

2015 ◽

Vol 112 (14) ◽

pp. 4195-4201 ◽

Cited By ~ 46

Author(s):

Shannon Stewart ◽

Tong-Wey Koh ◽

Arpan C. Ghosh ◽

John R. Carlson

Keyword(s):

Body Wall ◽

The Body ◽

Single Pair ◽

Taste Receptors ◽

Remarkable Feature ◽

Larval Stages ◽

Terminal Organ ◽

Drosophila Larva ◽

Developmental Dynamics ◽

Taste Organ

We examine in Drosophila a group of ∼35 ionotropic receptors (IRs), the IR20a clade, about which remarkably little is known. Of 28 genes analyzed, GAL4 drivers representing 11 showed expression in the larva. Eight drivers labeled neurons of the pharynx, a taste organ, and three labeled neurons of the body wall that may be chemosensory. Expression was not observed in neurons of one taste organ, the terminal organ, although these neurons express many drivers of the Gr (Gustatory receptor) family. For most drivers of the IR20a clade, we observed expression in a single pair of cells in the animal, with limited coexpression, and only a fraction of pharyngeal neurons are labeled. The organization of IR20a clade expression thus appears different from the organization of the Gr family or the Odor receptor (Or) family in the larva. A remarkable feature of the larval pharynx is that some of its organs are incorporated into the adult pharynx, and several drivers of this clade are expressed in the pharynx of both larvae and adults. Different IR drivers show different developmental dynamics across the larval stages, either increasing or decreasing. Among neurons expressing drivers in the pharynx, two projection patterns can be distinguished in the CNS. Neurons exhibiting these two kinds of projection patterns may activate different circuits, possibly signaling the presence of cues with different valence. Taken together, the simplest interpretation of our results is that the IR20a clade encodes a class of larval taste receptors.

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Feeding in tornaria larvae and the development of gill slits in enteropneust hemichordates

Canadian Journal of Zoology ◽

10.1139/z82-384 ◽

1982 ◽

Vol 60 (12) ◽

pp. 3010-3020 ◽

Cited By ~ 14

Author(s):

T. H. J. Gilmour

Keyword(s):

Body Wall ◽

Dorsal Surface ◽

Structure And Function ◽

The Body ◽

Flow Lines ◽

Water Currents ◽

Larval Stages ◽

Excess Water ◽

Preoral Lobe ◽

And Function

The food-collecting and waste-rejecting systems of the tornaria larval stages of enteropneust hemichordates are similar to those of larval and adult lophophorates and adult pterobranch hemichordates. Water entering the oral grooves is deflected towards the mouth and the impetus of heavy, potentially inedible particles may take them across the flow lines of the water currents inferred from the movements of suspended particles to impinge on cilia which reject them into the outgoing water currents. Lighter, potentially edible material remaining suspended in the deflected water currents is intercepted by cilia on an oral hood which is similar in structure and function to the preoral lobe of the actinotroch larvae of phoronids. Excess water carried into the mouth by cilia on the dorsal surface of the esophagus is rejected via lateral grooves which develop into pouches prior to metamorphosis. Following metamorphosis the pouches make contact with the body wall to form gill slits which continue to allow water to escape from the pharynx. This finding that the function of allowing excess water to escape is performed by lateral grooves in the esophagus of tornariae supports previous speculations on the evolution of gill slits and provides further evidence for relationships between lophophorates, hemichordates, and chordates.

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The external sensory morphology of the legs and hairplate system of female Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae)

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1987.0077 ◽

1987 ◽

Vol 232 (1268) ◽

pp. 323-366 ◽

Cited By ~ 13

Keyword(s):

Body Size ◽

Neck Region ◽

Dorsal Surface ◽

Parasitoid Wasp ◽

Ventral Surface ◽

Distal Portion ◽

The Body ◽

Single Pair ◽

Campaniform Sensilla ◽

Trichogramma Minutum

This work continues a comprehensive description of the external sensory morphology of the parasitoid wasp Trichogramma minutum . All sensilla and associated structures identified by electron microscopy are described. In addition, this study also includes the hairplates associated with the antennae and neck region. The majority of sensilla appear to be mechanosensory, and are either trichoid or campaniform in structure. Large, socketed setae (10–50 μm long) are found on all leg segments, but vary considerably in body size and shape, depending upon location. On the tibial and tarsal segments of the pro- and metathoracic legs some of the larger hairs have been modified to form antennal and wing combs. On both the meso- and metathoracic legs a distal tibial seta is greatly enlarged and functions as a socketed spur. The sensilla that compose the hairplates are relatively short (1–3 μm) and differ in socket morphology from the longer setae located elsewhere on the body surface. Hairplates occur on the dorsal surface of the trochanter at the coxatrochanteral joint, on the distal portion of the coxae, around the neck on the dorsal and ventral surfaces of the episternum, and the opening of the postocciput. The most complex arrangement of hairplates surrounds the distal portion of the scape, and comprises four separate groups of hairs. Hairplates are also located on the dorsal and lateral surfaces of the proximal end of the pedicellus. Nine to eleven campaniform sensilla are located on the trochanter of each leg. The proximal subdivision of the femur is equipped with six sensilla grouped together on the ventral surface. Three to five campaniform sensilla are clustered on the dorsal surface of the distal end of the tibia of each leg, and a single pair of sensilla is located at the distal end of the first tarsomere. All the leg campaniform sensilla are elliptical, and 1.5–2.5 μm long. The number, position and morphology of the sensilla was consistent between individuals. The structure and function of these sensory structures are discussed in relation to their role in walking, proprioceptive control of posture, and gravity detection. The scaling of sensilla to body size and homologies with larger insects are also examined, and the possible role of these structures in the detection and measurement of host curvature is considered.

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Seasonal biochemical composition of tissues from Cucumaria frondosa collected in the Bay of Fundy, Canada: feeding activity and reproduction

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315402005258 ◽

2002 ◽

Vol 82 (1) ◽

pp. 141-147 ◽

Cited By ~ 12

Author(s):

V.M.M. David ◽

B.A. MacDonald

Keyword(s):

Biochemical Composition ◽

Body Wall ◽

Feeding Activity ◽

The Body ◽

Bay Of Fundy ◽

Nutrient Storage ◽

Males And Females ◽

Post Spawning ◽

Spawning Periods ◽

Cucumaria Frondosa

This is the first study to examine the seasonal biochemical composition of tissues from male and female Cucumaria frondosa. Gonad and body wall tissues were analysed for their protein, lipid, and glycogen content. Lipids were the single most abundant component in gonad tissues, followed by proteins and glycogen, for both males and females. However, only protein and glycogen in the gonad tissues differed between feeding and non-feeding periods as well as between pre- and post-spawning periods. Proteins and lipids were both more abundant than glycogen in the body wall tissues. In this case, only protein and glycogen were found to differ between spawning states. All differences observed in the gonad tissues were attributed to the annual reproductive cycle, which produces a need for nutrient storage to allow the production of gametes throughout the year. The body wall was thought to be responsible for the build up of reserves during the feeding period in order to support maintenance and reproduction during non-feeding months.

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Electron Microscope Studies On the Body Wall and Feeding Apparatus of Longidorus Macrosoma 1)

Nematologica ◽

10.1163/187529269x00786 ◽

1969 ◽

Vol 15 (4) ◽

pp. 451-463 ◽

Cited By ~ 8

Author(s):

Hamdi Z. Aboul-Eid

Keyword(s):

Electron Microscope ◽

Body Wall ◽

The Body ◽

Feeding Apparatus

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Lymphangiomatosis of the Body Wall: A Report of Two Cases Associated with Chylothorax and Fatal Outcome

Fetal and Pediatric Pathology ◽

10.3109/15513819709168739 ◽

1997 ◽

Vol 17 (4) ◽

pp. 617-624 ◽

Cited By ~ 1

Author(s):

Philippe Moerman ◽

Chris Van Geet ◽

Hugo Devlieger

Keyword(s):

Body Wall ◽

Fatal Outcome ◽

The Body

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A screen for genetic loci required for body-wall muscle development during embryogenesis in Caenorhabditis elegans.

Genetics ◽

10.1093/genetics/137.2.483 ◽

1994 ◽

Vol 137 (2) ◽

pp. 483-498

Author(s):

J Ahnn ◽

A Fire

Keyword(s):

Caenorhabditis Elegans ◽

Myosin Heavy Chain ◽

Muscle Cell ◽

Heavy Chain ◽

Body Wall ◽

Muscle Development ◽

Contractile Function ◽

The Body ◽

Body Wall Muscle ◽

Genetic Loci

Abstract We have used available chromosomal deficiencies to screen for genetic loci whose zygotic expression is required for formation of body-wall muscle cells during embryogenesis in Caenorhabditis elegans. To test for muscle cell differentiation we have assayed for both contractile function and the expression of muscle-specific structural proteins. Monoclonal antibodies directed against two myosin heavy chain isoforms, the products of the unc-54 and myo-3 genes, were used to detect body-wall muscle differentiation. We have screened 77 deficiencies, covering approximately 72% of the genome. Deficiency homozygotes in most cases stain with antibodies to the body-wall muscle myosins and in many cases muscle contractile function is observed. We have identified two regions showing distinct defects in myosin heavy chain gene expression. Embryos homozygous for deficiencies removing the left tip of chromosome V fail to accumulate the myo-3 and unc-54 products, but express antigens characteristic of hypodermal, pharyngeal and neural development. Embryos lacking a large region on chromosome III accumulate the unc-54 product but not the myo-3 product. We conclude that there exist only a small number of loci whose zygotic expression is uniquely required for adoption of a muscle cell fate.

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