Crustacean parasites associated with hermit crabs from the western Mediterranean Sea, with first documentation of egg predation by the burrowing barnacle Trypetesa lampas (Cirripedia: Acrothoracica: Trypetesidae)

Abstract

Parasitic isopods (family Bopyridae) and burrowing barnacles (family Trypetesidae) infesting hermit crabs were investigated from shallow subtidal collections made along the southeastern coast of Spain in 2009. A total of 713 specimens of Clibanarius erythropus (Latreille, 1818) and 82 Calcinus tubularis (L., 1767) were examined. Gastropod shells and worm tubes inhabited by hermit crabs were collected by hand while snorkeling and were cracked to determine host species, size, sex and presence of eggs. Two species of bopyrid isopods were found on C. erythropus: the branchial parasite Bopyrissa fraiseii (Carayon, 1943) and the abdominal parasite Parathelges cardonae Codreanu and Codreanu in Codreanu, 1968. Among all C. erythropus examined, Bopyrissa fraiseii was found on 0.6% of hermit crabs and P. cardonae was found on 0.3%. A redescription of P. cardonae is provided and the species is documented with light and scanning electron microscopy for the first time. No Calcinus tubularis harbored parasitic isopods, but one specimen was parasitized by an unidentified rhizocephalan barnacle of the genus Septosaccus (1.2%). The burrowing barnacle Trypetesa lampas (Hancock, 1849) was found associated with both hermit crab species and evidence of predation on host eggs by this barnacle is shown for the first time. Trypetesa lampas was found in 4.2% of the shells collected. The present study expands our knowledge of the parasite fauna of hermit crabs from the Mediterranean Sea and indicates that additional research is needed to determine the impact of trypetesid egg predators on hermit crab populations.

New records of two trypetesid burrowing barnacles (Crustacea: Cirripedia: Acrothoracica: Trypetesidae) and their predation on host hermit crab eggs

“…The original description of the cushion states it is ‘wrinkled with fine, rounded ridges' (Tomlinson, 1955); when viewed using SEM, the cushion is actually composed of rows of sharp, blade-like denticules, possibly used to aid in food handling. These denticules are similar to those found in T. lampas (Williams et al , 2011) and the genus Tomlinsonia (Williams & Boyko, 2006).…”

“…IV; Tomlinson, 1969: 7, 11, 14–15, 17, 19–20, 22, 24–26, 28, 126, 131–132, 147, 150, 153, figure 36, table 2; White, 1969: 338; White, 1970: 29, 33, figure 2; Turquier & Carton 1976: 392; Newman & Abbott, 1980: 505–506, 509, 510, pl. 147; Grygier & Newman, 1985: 2, 18–19; Klepal, 1987: 251, 259–260, 294, 297; Barnes, 1989: 73–76, 78, table IV; Klepal, 1990: 362; Baluk & Radwánski, 1991: 1, 13, 22, 24, 30, 31, 32, 33, figure 7; Walker, 1992: 545, table 5 (in part); Anderson, 1994: 162, 178; Kozloff, 1996: 319; Williams & McDermott, 2004: 73–75, 90, table 1; Williams & Boyko, 2006: 294; Newman, 2007: 476, 481; Kolbasov & Høeg, 2007: 129–130, figures 3, 5, 11; Kolbasov, 2009: 16, 39, 41, 43, 46, 49, 57, 69, 81, 89, 97, 144, 147, 163, 168, 177, 197, 260, 338, 339, 394, 395, figures 8–10, 12, 15, 20, 23, 27, 29, 41, 49, 53, 60, 118, 150; Murphy, 2009: 5, 6, 8–10, 15, 19, 21, 24–26, 33, 34, 40–47, 55, 56, 58–60, 62–64, figures 1–9; Williams et al , 2011: 14. not Walker, 1992; table 5 ( T. lateralis from Puerto Rico is an error; it should be listed as T. lampas , as originally recorded by Seilacher, 1969).…”

“…Trypetesa spinulosa Turquier, 1976: 559–571, figures 1–9; Klepal, 1987: 258–259, 295, 297, 557; Klepal, 1990: 363, figure 4; Baluk & Radwánski 1991: 23, 24, 31, figure 8; Kolbasov, 1999: 142; Anderson, 1994: 162; Williams & McDermott, 2004: table 1; Williams & Boyko, 2006: 294, 296; Kolbasov, 2009: 18, 260, 338, 343, 394, figures 120, 150; Murphy, 2009: 5, 9, 19, 24, 47, 54–58, 61, 62, 66, figures 10–16; Williams et al , 2011: 14.…”

“…The cushions (also called ‘prominent excrescences': see Spivey, 1979, figure 2d; or ‘pillow-like hillocks': see Kolbasov, 2009, figure 27) are rounded protuberances on the distal end of the second segment of the terminal cirri that are covered in rows of small triangular denticules. Although they are easily observed on the cirri and have long been suspected to be involved in food processing (Darwin, 1854), their exact role in food capture or feeding remains unknown (Williams et al , 2011).

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The Global Diversity of Parasitic Isopods Associated with Crustacean Hosts (Isopoda: Bopyroidea and Cryptoniscoidea)

“…In addition to these major potential impacts on host reproduction, parasitic isopods may also affect the morphology and perhaps also the behavior of hosts. For example, members of Bopyridae that branchially infest decapods cause large swellings of their branchiostegites (see [44]; Figure 1B). Cryptoniscoids can also cause swellings in certain hosts such as pedunculate barnacles (see [21], Figure 12A).…”