Muscle architecture during the course of development ofDiplostomum pseudospathaceumNiewiadomska, 1984 (Trematoda, Diplostomidae) from cercariae to metacercariae

Abstract

Recent confocal microscopy studies have greatly expanded our knowledge of muscle systems in cercariae and adult digeneans, but the gross anatomy and development of metacercarial musculature remain relatively little known. To further our understanding of metacercarial development, this study used phalloidin staining and confocal microscopy to examine changes in muscle architecture over the course of development from cercariae to infective metacercariae in Diplostomum pseudospathaceum Niewiadomska, 1984. The paper describes muscle development in the body wall, anterior organ (oral sucker), acetabulum, pharynx and midgut and in the musculo-glandular organs that first appear in metacercariae (lappets and holdfast). The muscle architecture of the cercarial tail is also described. The results of the study support previously reported observations that diplostomid musculature undergoes substantial transformation during metacercarial development. The most profound changes, involving extensive remodelling and replacement of cercarial muscles, were seen in the body-wall musculature and in the anterior organ as it developed into the oral sucker. Muscle systems of other cercarial organs showed more gradual changes. The adaptive importance of developmental changes in musculature is discussed.

Possible mechanism of host manipulation resulting from a diel behaviour pattern of eye-dwelling parasites?

“…2003). Rather than relying on endogenous food reserves, active feeding by metacercariae on host tissue provides energy at the expense of the host for movement/migration, growth and development, and accelerated morphogenetic processes (Bullard and Overstreet, 2008;Petrov and Podvyaznaya, 2015, e.g. for pre-encysting metacercariae: Stumbo et al 2012).…”

“…Non-encysting metacercariae possess an elaborate morphology compared with their encysting counterparts, showing advanced organ development and a functioning gut, allowing for active feeding until host death or ingestion (Erasmus, 1972; Galaktionov and Dobrovolskij, 2003). Rather than relying on endogenous food reserves, active feeding by metacercariae on host tissue provides energy at the expense of the host for movement/migration, growth and development, and accelerated morphogenetic processes (Bullard and Overstreet, 2008; Petrov and Podvyaznaya, 2015, e.g. for pre-encysting metacercariae: Matisz and Goater, 2010; Stumbo et al 2012).…”

Somatic musculature in trematode hermaphroditic generation

“…However this is not the case for Cotylurus cornutus and any other Diplostomoidea, as they have complex metamorphosis of cercaria into metacercariae. In the course of such metamorphosis significant transformation of musculature was described recently in Diplostomum pseudospathaceum [ 35 ].…”

Neuromuscular organization and haptoral armament of Polyclithrum ponticum (Monogenea: Gyrodactylidae)

“…Body-wall musculature of several monogenean species (Halton et al, 1998;Zurawski et al, 2003;Halton & Maule, 2004) including gyrodactyloideans (El-Naggar et al, 2004Arafa et al, 2007) has been described by confocal microscopy as having outer circular, intermediate longitudinal and inner diagonal muscle layers. This muscle arrangement is the same as in Trematoda (Mair et al, 1998(Mair et al, , 2003Krupenko & Dobrovolskij, 2015;Petrov & Podvyaznaya, 2016;Nefedova et al, 2021), but differs from that of free-living flatworms ('turbellarians') where diagonal muscle fibres occupy an intermediate position between outer circular and inner longitudinal layers (Ehlers, 1985;Hooge, 2001;Tyler & Hooge, 2004). In Cestoda, the body-wall musculature appears to lack diagonal muscles, which is likely a derived condition (Halton & Maule, 2004;Rozario & Newmark, 2015;Mair et al, 2020).…”