Adult moulting and dimorphism in a new species of Sphenoderes (Kinorhyncha Kentrorhagata): Is the exception becoming the rule?
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Adult moulting and dimorphism in a new species of Sphenoderes (Kinorhyncha Kentrorhagata) : Is the exception becoming the rule? / Sørensen, Martin V.; Herranz, Maria.
In: Acta Zoologica, Vol. 103, No. 2, 2022, p. 150-166.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Adult moulting and dimorphism in a new species of Sphenoderes (Kinorhyncha Kentrorhagata)
T2 - Is the exception becoming the rule?
AU - Sørensen, Martin V.
AU - Herranz, Maria
PY - 2022
Y1 - 2022
N2 - Adult dimorphism (i.e. non-sexual dimorphism observed among sexually mature specimens) and the existence of two morphologically distinct adult stages are for the first time reported from a species of the kentrorhagid kinorhynch genus Sphenoderes. The dimorphism was found in a new species, Sphenoderes neptunus sp. nov., from the Gulf of Naples, Italy, and a formal description is provided. While dimorphism between adult life stages of kinorhynchs so far have been restricted to differences in the two posteriormost segments, the dimorphism in the new species is expressed in spine lengths throughout the entire trunk, as well as in presence or absence of cuspidate spines. The implications for comparative kinorhynch morphology and taxonomy are discussed, and it is concluded that adult dimorphism and the occurrence of more than one adult life stage always should be considered as a possibility when exploring kinorhynchs of the orders Kentrorhagata and Xenosomata. Despite the comparative challenges prompted by the adult dimorphism, species of Sphenoderes can still be distinguished by differences in shape of midventral placid and distribution of sensory spots. Conversely, spine patterns as differential characters should be used with caution, and only after ensuring that specimens belonging to the same adult stage are compared.
AB - Adult dimorphism (i.e. non-sexual dimorphism observed among sexually mature specimens) and the existence of two morphologically distinct adult stages are for the first time reported from a species of the kentrorhagid kinorhynch genus Sphenoderes. The dimorphism was found in a new species, Sphenoderes neptunus sp. nov., from the Gulf of Naples, Italy, and a formal description is provided. While dimorphism between adult life stages of kinorhynchs so far have been restricted to differences in the two posteriormost segments, the dimorphism in the new species is expressed in spine lengths throughout the entire trunk, as well as in presence or absence of cuspidate spines. The implications for comparative kinorhynch morphology and taxonomy are discussed, and it is concluded that adult dimorphism and the occurrence of more than one adult life stage always should be considered as a possibility when exploring kinorhynchs of the orders Kentrorhagata and Xenosomata. Despite the comparative challenges prompted by the adult dimorphism, species of Sphenoderes can still be distinguished by differences in shape of midventral placid and distribution of sensory spots. Conversely, spine patterns as differential characters should be used with caution, and only after ensuring that specimens belonging to the same adult stage are compared.
KW - dimorphism
KW - Kinorhyncha
KW - molting
KW - Scalidophora
KW - taxonomy
KW - CYCLORHAGID KINORHYNCH GENUS
KW - SP NOV.-A
KW - POSTEMBRYONIC DEVELOPMENT
KW - ECHINODERES KINORHYNCHA
KW - GROUND PATTERN
KW - LIFE-CYCLE
KW - REDESCRIPTION
U2 - 10.1111/azo.12361
DO - 10.1111/azo.12361
M3 - Journal article
VL - 103
SP - 150
EP - 166
JO - Acta Zoologica Online
JF - Acta Zoologica Online
SN - 1463-6395
IS - 2
ER -
ID: 251636518