DENDROMONOCOTYLE KEY

Dendromonocotyle key using Delta programme (taxonomic nomenclature)

Introduction:

The Monocotylid genus Dendromonocotyle is presently made up of 16 valid and 1 undescribed (preliminarily described) species. Monogeneans are parasitic flatworms that infest a wide range of fish hosts in both freshwater and marine environments. The monocotylid monogeneans are specific parasites of chondrychthyan fishes and the genus Dendromonocotyle Hargis, 1955 is the only genus known to parasitise the skin surface of their stingray hosts. Other monocotylids are gill parasites. Dendromonocotyle species can be destinguished from most of the other monocotylids by the presence of a dendritic intestinal caecum, hence the name "Dendro," meaning "tree-like." Dendromonocotyle species are problematic parasites in public aquaria around the world. Recently an overview of the South African Dendromonocotyle species introduced three new species. The following text key is the HTML from the Delta programme designed by Dallwitz, Paine and Zurcher (2006) and gives a basic breakdown of the descriptors to discriminate each species.

Glossary of terms:

Distal = end (part)
Proximal = beginning (part)
Loculus/loculi (see descriptive image)
Sclerotised/sclerotisation (comprising sclerotin)
Caecum = gut
Hamulus/hamuli = primary anchors on the haptor
Haptor = attachment disk of worm (posterior end)
Marginal papilla/papillae (see descriptive image)
Terminal papillary sclerite = small hook on end of the marginal papillae
Tripartite sclerite = sclerite with three processes often found at the junction of radial and inner or outer ring septa
Sclerite = attachment "hook" within the haptor (different types)

Dendromonocotyle template with basic labels:

Implicit Attributes

Unlessindicated otherwise, the following attributes are implicit throughout the descriptions, except where the characters concerned are inapplicable.

Dendromonocotyle citrosa Vaughan, Chisholm & Christison, 2007

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Sperm duct is straight within distal portion of male copulatory organ. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Two tooth like projections. Tripartite sclerites Unknown, orPresent at junction of inner-ring and radial septa only. Number of papillary sclerites Unknown, or 7 – 9. Ovary shape Unknown, or Ovoid. Vagina detail Unknown, or Proximal sclerotisation, or Bell-shaped sclerotised proximal portion. Host information Dasyatis chrysonota.

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Dendromonocotyle lulwane Vaughan, Chisholm & Christison, 2007

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Sperm duct within distal portion of male copulatory organ appears to split and cross over itself once, terminally. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs =7, posterior pair = 8. Terminal papillary scelrite With delicate tanslucent cup-shaped projections. Tripartite sclerites Unknown, or Present at junction ofinner-ring and radial septa only. Number of papillary scelerites Unknown, or 7– 9. Ovary shape Unknown, or Bi-lobed. Vagina detail Unknown, or Proximal sclerotisation, or Criss-crossed proximal sclerotised portion. Host information Himantura gerrardi.

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Dendromonocotyle colorni (South African population)

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Distal portion of male copulatory organ with sclerotised accessory filament. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral pair = 6, posterolateral pair = 8, posterior pair = 8. Terminal papillary scelrite Third process visible. Tripartite sclerites Unknown, or Present at junction of inner and outer-ring septa and radial septa. Number of papillary sclerites Unknown, or 3 – 4. Ovary shape Unknown, or Bi-lobed.Vagina detail Unknown, or Distinct coiled translucent duct present. Host information Himantura uarnak.

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Dendromonocotyle colorni Chisholm, Whittington & Kearn, 2001 (Israel)

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Distal portion of male copulatory organ with unsclerotised accessory filament. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair= 6, anterolateral pair = 6, posterolateral pair = 8, posterior pair = 8. Terminal papillary scelrite Third process visible. Tripartite sclerites Unknown, or Present at junction of inner-ring and radial septa only. Number of papillary sclerites Unknown, or 2 – 3. Ovary shape Unknown, or Bi-lobed. Vagina detail Unknown, or Distinct coiled translucent duct present. Host information Himantura uarnak.

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Dendromonocotyle ukuthena Vaughan, Chisholm & Christison, 2007

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Sperm duct within distal portion of male copulatory organ criss-crossed. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Third process visible. Tripartite sclerites Unknown, or Present at junction of inner and outer-ring septa and radial septa. Number of papillary sclerites Unknown, or 5 – 6. Ovary shape Unknown, or Bi-lobed. Vagina detail Unknown, or Proximal sclerotisation, or Armed distal portion within chamber: Large sclerites present. Host information Himantura gerrardi, or Himantura uarnak.

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Dendromonocotyle bradsmithi Chisholm, Glennon & Whittington, 2005

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Sperm duct within distal portion of male copulatory organ criss-crossed and has sclerotised accessory flange. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Unknown, or Present at junction of inner and outer-ring septa and radial septa. Number of papillary scelerites Unknown, or 6 – 8. Ovary shape Unknown, or Bi-lobed. Vagina detail Unknown, or Proximal sclerotisation. Host information Myliobatis australis.

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Not a Dendromonocotylid

Monogenean ectoparasite Skate host, or Guitarfish host, or Obvious or large/pronounced hamuli, or Parasite of gill tissue, or Haptor round to oval shape without defined loculi, or No dendritic intestinal caecum. Marginal hooklets 16 Number. Marginal papillae Unknown. Tripartite sclerites Unknown. Number of papillary sclerites Unknown. Ovary shape Unknown. Vagina detail Unknown.

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Dendromonocotyle lasti Chisholm and Whittington, 2004

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Distal portion of male copulatory organ with coiled sclerotised filament. Muscular sheath with crown of sclerotised spines. Marginal papillae Unknown, or 38 marginal papillae. Locular to papillae arrangement Anterior pair = 4, anterolateral and posterolateral and posterior pair = 5. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Unknown, or Absent. Number of papillary sclerites Unknown, or 3 – 4. Ovary shape Unknown, or Bi-lobed. Vagina detail Unknown, or Distal portion with thick muscular inner wall. Host information Himantura sp.

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Dendromonocotyle centrourae Cheung & Whittaker, 1993

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Very short entire male copulatory organ length ending in a spout. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Third process visible. Tripartite sclerites Unknown, or Present at junction of inner-ring and radial septa only. Number of papillary sclerites Unknown, or 6 – 8. Ovary shape Unknown, or Irregular. Vagina detail Unknown. Host information Dasyatis centroura.

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Dendromonocotyle octodiscus Hargis, 1955

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Distal portion tapers to a point, has sclerotised projection, and is encircled by a spiral filament. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Unknown, or Present at junction of inner-ring and radial septa only. Number of papillary sclerites Unknown. Ovary shape Unknown, or Bi-lobed. Vagina detail Unknown, or Proximal sclerotisation, or Spherical bulb present. Host information Urolophus jamaicensis, or Dasyatis marmorata, or Dasyatis say.

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Dendromonocotyle californica Olson & Jeffries, 1983

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Distal portion of malec opulatoiry organ splits into two. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Not all radial septa join the central loculus at the central septum, or Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Unknown, or Absent. Number of papillary sclerites Unknown. Ovary shape Unknown, or Irregular. Vagina detail Unknown, or Proximal sclerotisation. Host information Myliobatis californica.

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Dendromonocotyle ardea Chisholm & Whittington, 1995

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Distal portion spiralling once distal to distinct flaring accessory filaments. Marginal papillae Unknown, or 42 marginal papillae. Locular to papillae arrangement Variable between left andright loculi. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Unknown, or Absent. Number of papillary sclerites Unknown. Ovary shape Unknown, or Irregular. Vagina detail Unknown, or Proximal portion sclerotised, but distinctive with funnel shaped structure. Host information Pastinachus sephen.

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Dendromonocotyle akajeii Ho & Perkins, 1980

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Distal portion looping twice then narrowing to a point. Spiral accessary filament present. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair= 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Unknown. Number of papillary sclerites Unknown. Ovary shape Unknown. Vagina detail Unknown, or Sclerotised along its length, looping twice and narrowing proximally. Host information Dasyatis akajei.

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Dendromonocotyle cortesi Bravo-Hollis, 1969

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Sperm duct within distal portion loops once before straightening. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Two tooth like projections. Tripartite sclerites Unknown, or Absent. Number of papillary sclerites 5 – 7, or Unknown. Ovary shape Unknown, or Ovoid. Vagina detail Unknown, or Proximal sclerotisation. Host information Unknown.

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Dendromonocotyle kuhlii Young, 1976

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Distal portion simple, narrowing to a point. not sclerotised. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite One process only, keyhole shaped. Tripartite sclerites Unknown. Number of papillary sclerites 2 only, or Unknown. Ovary shape Unknown, or Bi-lobed. Vagina detail Simple, straight, or Unknown. Host information Dasyatis kuhli.

Dendromonocotyle pipinna Chisholm & Whittington, 2004

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Male copulatory organ short. Distal portion with small sclerotised ridges. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Absent. Number of papillary sclerites 5 – 8, or Unknown. Ovary shape Tri-lobed, or Unknown. Vagina detail Narrow distal part inflating and narrowing again proximally, not sclerotised, or Unknown. Host information Taenuira meyeni.

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Dendromonocotyle torosa Chisholm & Whittington, 2004

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Distal end inflated with thick sclerotised wall. Marginal papillae Unknown, or 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs =7, posterior pair = 8. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Unknown, or Present at junction of inner-ring and radial septa only. Number of papillary sclerites 5 – 7, or Unknown. Ovary shape Unknown, or Bi-lobed. Vagina detail Small funnel-shaped sclerotised proximal section, or Unknown. Host information Aetobatus narinari.

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Dendromonocotyle taeniurae Euzet & Maillard, 1967

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Absent. Distal portion of male copulatory organ Distal portion of male copulatory organ widens before splitting in two. Marginal papillae Unknown, or 42 marginal papillae. Locular to papillae arrangement Variable between left and right loculi. Terminal papillary scelrite Two processes (horn-like). Tripartite sclerites Present at junction of inner and outer-ring septa and radial septa. Number of papillary sclerites 6 – 9. Ovary shape Unknown, or Bi-lobed.Vagina detail Sclerotised spines at entrance to vagina, or Sclerotised spines at the entrance to the vagina, Vagina widens slightly beforte narrowing proximally, or Unknown. Host information Taeniura grabata.

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Dendromonocotyle sp. 1 Vaughan, Chisholm & Christison (undescribed)

Monogenean ectoparasite Stingray host, or Very small or absent hamuli, or Parasite of skin surface, or Haptor round to oval shape with 8 peripheral loculi, or Dendritic intestinal caecum. Marginal hooklets 14 Number. Humuli Present. Distal portion of male copulatory organ Sperm duct within distal portion of male copulatory organ criss-crossed. Marginal papillae 56 marginal papillae. Locular to papillae arrangement Anterior pair = 6, anterolateral and posterolateral pairs = 7, posterior pair = 8. Terminal papillary scelrite Third process visible. Tripartite sclerites Absent. Number of papillary scelerites 5– 6. Ovary shape Unknown, or Bi-lobed. Vagina detail Sclerotised spines at entrance to vagina, or Unknown. Host information Dasyatis chrysonota.

David Vaughan
Senior quarist, Quarantine
Two Oceans Aquarium
Cape Town, South Africa
+27 21 418 38 23
dvaughan@aquarium.co.za

Picture credits:

Chisholm, Glennon & Whittington 2005. Dendromonocotyle bradsmithi n. sp. (Monogenea: Monocotylidae) from the skin of Myliobatis australis (Elasmobranchii: Myliobatidae) off Adelaide and Perth, Australia: description of adult and larva. Zootaxa 951: 1 - 15.

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Cite this publication as: ‘My_Authors (2000 onwards). ‘My_Title: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 21st September 2000.