| 1. |
- Berggren, Matz S., 1950
(författare)
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Periclimenes nomadophila and Tuleariocaris sarec, two new species of pontoniine shrimps (Crustacea: Decapoda: Pontoniinae), from Inhaca Island, Moçambique
- 1994
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Ingår i: Journal of Crustacean Biology. - 0278-0372. ; 14:4, s. 782-802
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Tidskriftsartikel (refereegranskat)abstract
- Two new species of pontoniine hrimps from Moçambique are described and illustrated. The first species, Periclimenes nomadophila, is the third pontoniine species found to be associated with scyphozoans and the first record of association with a pelagic jellyfish (Rhopilema nomadica). Character differences between closely related species are tabulated and a key to the different species in the Periclimenes obscurus group is presented. The second described species, Tuleariocaris sarec, is the fourth species in its genus. All are associated with sea urchins. Tuleariocaris sarec clings tightly head down, to the spines of its host. A key to the species of the genus Tuleariocarisis presented.
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| 2. |
- Berggren, Matz S., 1950
(författare)
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The little-known shallow-water shrimp, Notopontonia platycheles Bruce, 1991 (Crustacea: Decapoda: Pontoniinae).
- 1999
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Ingår i: Journal of Crustacean Biology. - 0278-0372. ; 19:1, s. 180-187
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Tidskriftsartikel (refereegranskat)abstract
- The discovery of the "red-lipped sea squirt" Herdmania momus, as the host species for Notopontonia platycheles from the southern coast of Western Australia made it possible to confirm and add to the original species description. The shape of the large flattened chela of the second pereiopods is shown to be an ontogenetic development in both males and females. The final shape is accomplished with an increased growth of the ventral carina. The shrimp is a temperate species that extends it distribution up to Shark Bay (about 26?S) on the western coast of Australia. The majority of host tunicates were found with a single individual of N. platycheles inside, contrary to the usual situation of associated shrimps living in pairs. The shrimp often shares the branchial chamber of its host with other decapod crustaceans, indicating that it may migrate out of or between the host tunicates. In some tunicates at Shark Bay, a few specimens of Dasella ansoni were found. This is the first discovery of this species since the type specimens were found in the Arafura Sea.
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| 3. |
- Elofsson, Rolf
(författare)
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A Non-Ciliary Receptor in the Mandible of a Mystacocarid Crustacean, Derocheilocaris Typica
- 2015
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Ingår i: Journal of Crustacean Biology. - 0278-0372. ; 35:4, s. 504-510
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Tidskriftsartikel (refereegranskat)abstract
- The mystacocarid crustacean Derocheilocaris typica Pennak and Zinn, 1943 lives in sand interstices and is less than one mm long. It is unique among Arthropoda. It has sensory cells in the mandible, which lack cilia. The function as mechano- and/or chemo-receptors has been replaced by dendrites, the sensory cell protrusions carrying cilia. The dendrites swell, flatten, and fill the endite- a medial outgrowth from the mandible, which is the main masticating appendage. The dendrites have many contacts with the inside of the cuticle, which insures close proximity to the food outside the body. Another feature specific to D. typica is the reduced cilia in the cuspidate setae of the food handling appendages: first and second maxillae, and maxilliped. The remaining approximate 50 setae on the body, not related to food handling, conform to those of all arthropods.
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| 4. |
- Elofsson, Rolf
(författare)
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Evolution of organ systems in the Crustacea: Mystacocarida and Cephalocrida in retrospect
- 2019
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Ingår i: Journal of Crustacean Biology. - : Oxford University Press (OUP). - 0278-0372 .- 1937-240X. ; 39:2, s. 91-97
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Tidskriftsartikel (refereegranskat)abstract
- The morphology of the internal organs of two representative species of the crustacean classes Mystacocarida, Derocheilocaris typica (Pennak & Zinn, 1943), and Cephalocarida, Hutchinsoniella macracantha (Sanders, 1955), has been studied ultrastructurally from 1990 onwards. A review of the subject offers a unique opportunity to compare and contrast the two taxa at a time when their key positions in discussions of crustacean relationships and evolution makes any new knowledge particularly valuable. The same internal organ or organ system can be constructed very differently in the two groups, but similarities also occur. Both the similarities and differences suggest functional interpretations and shed light on evolutionary pathways. The importance of including anatomy and functional morphology in phylogenetic discussions is emphasized.
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| 5. |
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| 6. |
- Elofsson, Rolf
(författare)
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Sensory morphology in the antennae of the cephalocarid Hutchinsoniella macracantha (Crustacea)
- 1991
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Ingår i: Journal of Crustacean Biology. - 0278-0372. ; 11, s. 345-355
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Tidskriftsartikel (refereegranskat)abstract
- The first antenna of Hutchinsoniella macracantha is a 6-segmented, uniramous appendage carrying 1 aesthetasc and 22 setae (or sensilla). The second antenna is biramous and has approximately 80 setae. The sensory cells of the first antenna are arranged in 3 clusters in the first and second segments; one cluster serving the aesthetasc (approximately 130 cells), one the 11 setae of the sixth segment (approximately 100), and one the remaining setae (approximately 80). The sensory cells of the second antenna are distributed in a medial band along the length of the antenna. The sensory cells of the aesthetasc have 1 cilium each which splits into many branches. The sensory cells of the setae have 1 unbranched cilium each, and the number of sensory cells varies for each seta. The aesthetasc is a presumed olfactory organ, and all setae display features suggesting chemoreception. The aesthetasc combines malacostracan and nonmalacostracan features, whereas the setae conform to a general crustacean pattern.
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| 7. |
- Elofsson, Rolf, et al.
(författare)
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Sensory structures associated with the cuticle of Hutchinsoniella macracantha (Crustacea, Cephalocarida)
- 1994
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Ingår i: Journal of Crustacean Biology. - 0278-0372. ; 14, s. 454-462
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Tidskriftsartikel (refereegranskat)abstract
- The body cuticle of the cephalocarid crustacean Hutchinsoniella macracantha Sanders, 1955, carries two types of small setae which differ in their external shape and number of ciliated sensory cells. It also has two types of pores, one being a gland opening, the other containing the tip of a cilium. The setae and the pore type containing a ciliated sensory cell are considered chemosensory organs.
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| 8. |
- Elofsson, Rolf, et al.
(författare)
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Tegumental glands of Hutchinsoniella macracantha (Cephalocarida)
- 1998
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Ingår i: Journal of Crustacean Biology. - 0278-0372. ; 18, s. 42-56
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Tidskriftsartikel (refereegranskat)abstract
- Three types of tegumental glands of Hutchinsoniella macracantha body, limb, and caudal, are described for the first time. Previously described salivary and cement glands also belong to this category. All have the same fundamental construction. They consist of 1 or 2 secretory cells opening into a short cuticular channel ending in a pore. The channel is Formed by a sheath or canal cell and an intermediate cell. The intermediate cell has an actin-like filament bundle encircling the duct. If is a type of tricellular tegumental gland common in crustaceans. The secretory cells can be very large, the caudal gland in the cerci being 0.5-0.6 mm in length. They are, at least distally, completely filled with secretory granules. Some contain enormous Golgi-like bodies. The secretory cells vary in cytological details and granular secretion, both within a pair and depending on body position. It is concluded that a common gross morphology of the tegumental glands of Hutchinsoniella houses different functions.
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| 9. |
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| 10. |
- Elofsson, Rolf, et al.
(författare)
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The digestive system of the cephalocarid Hutchinsoniella macracantha (Crustacea)
- 1992
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Ingår i: Journal of Crustacean Biology. - 0278-0372. ; 12, s. 571-591
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Tidskriftsartikel (refereegranskat)abstract
- The digestive tract of the cephalocarid Hutchinsoniella macracantha begins with an atrium oris, posterior to the mouth. The esophagus loops up through the head and ends with a valve to the midgut. The epithelial cells and cuticle of both these structures are connected with long, winding, apically distended microvilli. The midgut is a straight tube with a pair of diverticula anteriorly. Midgut epithelial cells have microvilli, light vesicles, and a peculiar endoplasmic reticulum that is produced into a palisade of extensions toward the apical surface. Outside the basal lamina are muscle and peri-intestinal cells which send fingerlike projections into the basal portion of the midgut epithelial cells. The rectum joins the midgut near the end of the eighteenth segment and consists of unspecialized epithelial cells. In spite of the simple gross morphology the digestive tract has a complicated musculature. Circular muscles follow the whole tract including the diverticula. Radial muscles attach to the esophagus and rectum. Many longitudinal muscles are found inside the circular muscles in the anterior part of the midgut but only a few outside posteriorly. Gland cells occur in the labrum and diverticula. Absorption of nutrients seems to be limited to the midgut epithelial cells. Metabolites are transported via their endoplasmic reticulum to that of the peri-intestinal cells.
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