Development, morphology and ultrastructure of the branchial crown of Fabricia stellaris (Müller, 1774) (Polychaeta: Sabellida: Fabriciinae)

2011 ◽  
Vol 93 (4) ◽  
pp. 409-421 ◽  
Author(s):  
Nadine Randel ◽  
Andreas Bick
Keyword(s):  
Branchial Crown

Memoirs: The Development of the Serpiilid Pomatoeeros Triqueter L

1941 ◽  
Vol s2-82 (327) ◽  
pp. 467-540 ◽  
Author(s):  
F. SEGROVE
Keyword(s):  
Body Wall ◽  
Feeding Activity ◽  
Dorsal Surface ◽  
The Body ◽  
Single Pair ◽  
Feeding Apparatus ◽  
Food Material ◽  
Locomotor Apparatus ◽  
Adult Feeding ◽  
Branchial Crown

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.

Redescription of Chone infundibuliformis Krøyer, 1856 (Polychaeta: Sabellidae) and histology of the branchial crown appendages, collar and glandular ridge

Zootaxa ◽  
2006 ◽  
Vol 1115 (1) ◽  
pp. 31 ◽  
Author(s):  
MARÍA A. TOVAR-HERNÁNDEZ ◽  
TERESA SOSA-RODRÍGUEZ
Keyword(s):  
Blood Vessels ◽  
Type Species ◽  
Hyaline Cartilage ◽  
Original Description ◽  
Glandular Epithelium ◽  
Dorsal Vessel ◽  
Misleading Information ◽  
Branchial Crown ◽  
Dense Mass ◽  
Thoracic And Abdominal

Fifty-three species have been formally described in Chone Krøyer, 1856, showing wide variation in the shapes of dorsal lips, peristomium, and posterior abdominal uncini. Previous studies indicate that such variation could result in splitting of the genus; however, the original description of the type species, C. infundibuliformis did not include critical details and illustrations, and for other species, incomplete or misleading information has been provided. In order to redescribe the species C. infundibuliformis and delineate the genus, type and topotype materials were reviewed, and histological sections of the appendages of the branchial crown, collar and glandular ridge are described. The redescription points out that in C. infundibuliformis: 1) insertion of the branchial lobes is not exposed beyond the collar; 2) radioles have a paired series of pinnules of different sizes; 3) radiolar flanges are broad; 4) dorsal lips are broadly rounded, as long as wide, without mid-rib; they have hyaline cartilage, but there is no extension of the branchial skeleton; 5) dorsal lips are vascularized by a plexus of small blood vessels derived from the basal branchial blood vessels, which further back communicate with the dorsal vessel; 6) thoracic uncini have teeth above the main fang of unequal size, median tooth of basal row larger than teeth in subsequent rows; 7) uncinus shape shows variation within each torus, but no intersegmental gradation is appreciable; 8) females with oocytes distributed in all thoracic and abdominal segments; males with sperm in abdomen, with barrel-shaped nucleus and mushroom-shaped acrosome. The collar is supported by a dense mass of hyaline cartilage and covered by glandular epithelium composed of basophile glands. Acidophil glands, tubular-shaped with granulose secretions, constitute the glandular ridge. Size of teeth in thoracic uncini, presence or absence of abdominal uncini variation, latero-ventral posterior abdominal depression, dorsal lips internal construction and glandular ridge are compared among some species of Chone and close genera.

scholarly journals Sabella Pavonina Savigny Var. Bicoronata Hornell and the Genus Spirographis Viviani (Polychaeta, Sabellidae)

1946 ◽  
Vol 26 (3) ◽  
pp. 426-431 ◽  
Author(s):  
D. W. Ewer
Keyword(s):  
Branchial Crown ◽  
Two Sides

A variety of Sabella pavonina Sav. described by Hornell as bicoronata has been found at Plymouth. It is characterized by the unequal development of the two sides of the branchial crown. The characters by which Sabella pavonina, its variety bicoronata and Spirographis spallanzanii may be distinguished are described. It is concluded that the genus Spirographis is not valid and that its species should be referred to the genus Sabella which is redefined.

Kirkia heterobranchiata, a new genus and species of extratubular brooding sabellid (Polychaeta: Sabellidae) from São Paulo, Brazil

2004 ◽  
Vol 84 (4) ◽  
pp. 701-710 ◽  
Author(s):  
João M. de M. Nogueira ◽  
Eduardo López ◽  
Maíra C.S. Rossi
Keyword(s):  
Phylogenetic Analysis ◽  
New Genus ◽  
Sao Paulo ◽  
São Paulo ◽  
New Genus And Species ◽  
Branchial Crown

A new genus and species of sabellid polychaete from an organically enriched beach in São Sebastião, State of São Paulo, is described. Kirkia heterobranchiata is unique among sabellids for brooding the embryos on the dorsalmost pair of radioles, which exhibits several modifications for this purpose, rather than on ventral radioles. Morphologically, K. heterobranchiata is most closely related to Perkinsiana riwo, here referred to as the new genus, as suggested by phylogenetic analysis. The new genus is characterized by the shape of the lips (dorsal lips roughly triangular, broader than long; ventral lips lower, ventrally fused and distally rounded), by the absence of both radiolar and pinnular appendages, by having uncini with very short handles in both the thorax and abdomen, and by the ability to brood embryos in cocoons attached to the branchial crown.

Description of a new species of Sabellidae (Polychaeta, Annelida) from fresh and brackish waters in Europe, with some remarks on the branchial crown of Laonome

Zootaxa ◽  
2018 ◽  
Vol 4483 (2) ◽  
pp. 349 ◽  
Author(s):  
ANDREAS BICK ◽  
RALF BASTROP ◽  
JONNE KOTTA ◽  
KARIN MEIßNER ◽  
MARIA MEYER ◽  
...  
Keyword(s):  
Dna Sequences ◽  
River Estuary ◽  
The Other ◽  
Type Material ◽  
The Baltic Sea ◽  
Brackish Waters ◽  
Don River ◽  
Branchial Crown ◽  
The Baltic ◽  
A New Species

In 2009, a hitherto unknown Laonome species was found in the Canal Ghent-Terneuzen in the Netherlands and subsequently in other Dutch rivers, canals and estuaries. A few years later, more unknown Laonome specimens were found in the eastern part of the Baltic Sea and in the Don River estuary, Sea of Azov. Initially, it was assumed that these specimens could represent Laonome calida Capa, 2007, originally described from Australia. In the present study we examine all these unknown European Laonome specimens and compare these specimens with the type material of L. calida from Australia. This lead to two main results: First, all specimens from Europe have the same diagnostic characters and therefore belong to one species. This finding was also supported by the results of a correspondence analysis, and genetic analyses using four different DNA sequences (COI, 16S, 28S). Second, it turned out that the type material of L. calida contains two morphologically distinct groups of specimens. The holotype and 7 paratypes are similar to each other but differ significantly from the other also similar 16 paratypes, and from all European specimens. On the basis of these observations, the Laonome specimens from European waters are described here as L. xeprovala sp. nov. We also provide the characters of the branchial crown of three Laonome species for a prospective revision of this genus. 

Anaesthetization and fixation effects on the morphology of sabellid polychaetes (Annelida: Polychaeta: Sabellidae)

2007 ◽  
Vol 87 (5) ◽  
pp. 1127-1132 ◽  
Author(s):  
Elisa Maria Costa-Paiva ◽  
Paulo Cesar Paiva ◽  
Michelle Klautau
Keyword(s):  
Multivariate Statistics ◽  
Magnesium Chloride ◽  
Morphological Characters ◽  
The Body ◽  
Control Group ◽  
Morphometric Characters ◽  
Canonical Variables ◽  
Branchial Crown

One hundred and four specimens of Branchiomma luctuosum (Grube, 1870), a sabellid polychaete, were submitted to different anaesthetization and fixation procedures: a control group with living animals, immediate fixation with formaldehyde 4% (FO), ethanol 100% (AE) or ethanol 70% (ET), and anaesthetization with magnesium chloride (MC), refrigeration (RE), menthol crystals (ME) or freshwater (FW). Twenty-three morphometric variables of the body were measured and analysed with size-free multivariate statistics. The first three canonical variables explained 80% of the variation, being significantly correlated with 19 measured variables, mainly those related to the shape of the body setigers. Besides morphometric variables, some morphological characters commonly used in polychaete taxonomy also presented variation among fixation procedures, such as the release of parapodial elements and the integument. Among the procedures tested, AE, ET and FW were the best in approximating the shape of living specimens. Specimens submitted to FO and RE had shorter, wider, and thicker bodies, whereas those submitted to MC and ME were more elongated, narrower, flatter, and had wider pygidia than living specimens. Lengths of branchial crown, setiger 1 and pygidium seem to be the most informative morphometric characters for taxonomic purposes since they did not present deformation due to fixation procedures.

Développement morphologique et croissance des juvéniles de l'Owenia fusiformis Delle Chiaje (Polychaeta, Oweniidae)

1992 ◽  
Vol 70 (9) ◽  
pp. 1701-1711 ◽  
Author(s):  
Éric Thiébaut ◽  
Jean-Claude Dauvin
Keyword(s):  
Size Distribution ◽  
Larval Stage ◽  
Individual Growth ◽  
Morphological Development ◽  
English Channel ◽  
Demographic Structure ◽  
Differential Growth ◽  
Total Length ◽  
Branchial Crown ◽  
Over Time

The morphological development of the branchial crown and uncinigerous tori, growth, and demographic structure were observed in juveniles of Owenia fusiformis Delle Chiaje, 1841 from the Bay of Seine (eastern English Channel). Growth becomes significant only after one and a half months of benthic life; individual growth is highly variable and results in a progressive widening of the size distribution of the population over time. From six initial branches present at the post-larval stage, seven stages of branchial development can be distinguished. The branchial crown develops by successive dichotomous divisions and growth of the new branches. The number of dichotomous divisions (D) increases with total length (LT) and age (A): D = 1.718 ln(LT) − 0.291; D = 0.987 ln(A) − 1.471. The number of uncinigerous tori (T) increases with total length (LT) and age (A): T = 4.272 ln(LT) + 7.272; T = 4.477 ln(A) − 2.479. The acquisition of fully grown characters after metamorphosis was progressive and depended more on total length of the juvenile than on age. At any given age, there was an important variability in investigated characters because of differential growth of juveniles. Ecological consequences resulting from interactions between morphological development and growth with respect to recruitment are discussed.

Aspects of the feeding biology of the fanworm Bispira volutacornis (Polychaeta: Sabellidae)

2003 ◽  
Vol 83 (3) ◽  
pp. 453-456 ◽  
Author(s):  
Róisín Nash ◽  
Brendan F. Keegan
Keyword(s):  
Particulate Matter ◽  
Alimentary Canal ◽  
Current Flow ◽  
One Dimension ◽  
Predatory Fish ◽  
Feeding Apparatus ◽  
Ample Evidence ◽  
Feeding Biology ◽  
Branchial Crown ◽  
Vacuolated Cells

The detail of the characteristic double whorled branchial crown of the tubiculous polychaete Bispira volutacornis, with its internal skeleton of large vacuolated cells and ciliated radioles, is consistent with the feeding apparatus of sabellids at large. Studies show that ingested particulate matter has at least one dimension less than 15 μm. Feeding seems to be most readily accommodated at current speeds from 1 cm s−1 to 3 cm s−1 with the crown apex angled downstream. Particulate matter passes through the alimentary canal in 7·7 h at 14°C, for an average sized specimen of 97 segments. Whilst the tube provides protection against predatory fish and crustaceans (with ample evidence of sub-lethal cropping of the branchial crown), it also has a role in irrigation and respiration. The worm will retreat within the tube when current flow exceeds 8·7 cm s−1.

Sign in / Sign up

Export Citation Format

Share Document