Plocamopherus maderae (Lowe, 1842)
Class: Gastropoda Cuvier, 1797
Subclass: Heterobranchia J.E. Gray, 1840
Clade: Euthyneura Spengel, 1881
Clade: Nudipleura Wägele & Willan, 2000
Order: Nudibranchia Cuvier, 1817
Suborder: Euctenidiacea Tardy, 1970
Infraorder: Doridacea Thiele, 1931
Superfamily: Polyceroidea Alder & Hancock, 1845
Family: Polyceridae Alder & Hancock, 1845
Subfamily: Triophinae Odhner in Franc, 1968
Genus: Plocamopherus Rüppell & Leuckart, 1828
Species: Plocamopherus maderae (Lowe, 1842) [Peplidia]
- Peplidia maderae Lowe, 1842
This is a spectacular nudibranch as it can reach more than 50 mm in length. The initial morphological description of the species described it as an orange or yellowish-orange nudibranch, with numerous small dark brown spots throughout the body and, in a less defined way, patched orange spots. In young specimens, the body color is translucent yellow to reddish-brown, similar to the color pattern of Thecacera pennigera (Ortea et al., 1996). The cephalic veil has 6-8 short, branched digitations. The rhinophores are coloured similar to the body, have lamellae in the upper half and a tapered basal stem. The edge of the mantle has three pairs of branched papillae, two pairs located in front of the gill and the third pair located just behind the gill; these papillae have a white or slightly pink pigment that may also appear on the sides of the body and tail. The tail is robust, long and flat, and has a dorsal keel that the animal can use for swimming. The gills are large, of the same color of the body, they are slightly branched and erect.
This species is capable of swimming by using its tail and also by flexing the body laterally (Newcomb et al, 2012). This nudibranch is typically nocturnal, hiding under rocks in shallow water during the day (Lowe, 1842; Eliot, 1906; Ortea et al, 1992;. Palomar et al, 2014). The most important feature of this species is its bioluminescence. Throughout the posterior midline, from the back edge of the notum to the tip of the tail, it has a line that emits phosphorescent light flashes when the individual is disturbed or swims away. The edges of the gills have the same effect as do the lateral papillae, emitting powerful luminescence flashes when the individual is disturbed. This bioluminescence is intrinsic, which means that the light output depends on the animal’s own biochemical processes without symbiotic association with bacteria. Another bioluminiscent species is Kaloplocamus ramosus, whose chemical bioluminescence reaction takes place within the luminescent cells or photophores (intracellular luminescence), while in the species Plocamopherus maderae, chemical luminescent chemical reaction occurs outside the cells (extracellular luminescence) (Valles et al., 2006). The most consistent explanation for this bioluminescence occurring only when the animal is disturbed is, according to Wilbur and Yonge (1966), to temporarily distract potential predators. However, based on personal observations, bioluminescence is often seen during night dives in individuals that were not being disturbed, so it could be a communication system between individuals of the same species for breeding purposes. The spawn is a ribbon wound up in a spiral with 5 turns and orange eggs (Medslugs).
- Plocamopherus. From Greek “plokamos”, hair tress + “-pherus”, from Latin “fero”, a combining form meaning “bearing”, “producing”, “yielding”, “containing”, “conveying” used in the formation of compound words.
- Maderae, from Madeira.
This species was first described in Madeira, and then only registered in the Canary Islands (Cervera et al, 2004) and Cape Verde (Eliot, 1906), so that its distribution seems to be limited to the biogeographical unit known as Macaronesic Region.
| : OBIS|
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
| : OPK|
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions
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