Microcotyle archosargi MacCallum, 1913

Mendoza-Franco, Edgar F., Tun, Mariela del Carmen Rosado, Anchevida, Allan de Jesus Duarte & Rodriguez, Rodolfo E. del Rio, 2018, Morphological and molecular (28 S rRNA) data of monogeneans (Platyhelminthes) infecting the gill lamellae of marine fishes in the Campeche Bank, southwest Gulf of Mexico, ZooKeys 783, pp. 125-161 : 125

Microcotyle archosargi MacCallum, 1913

Type host.

Archosargus probatocephalus

Present study.

A. rhomboidalis (new host)

Locality/prevalence, mean abundance and intensity range.

San Francisco: 17 fish (mean TL 26.9 cm; range 17-23.6) infected of 18 examined (94.4 %); abundance, 4; intensity of infection, 2-6 worms. Seyba Playa: 23 fish (TL 28.4; 19.2-30.5) infected of 25 examined (92 %); abundance, 5; intensity of infection, 5-6. Champoton: 39 fish (TL 28.2; 24.7-30.5) infected of 45 examined (86.6 %); abundance, 4; intensity of infection, 3-9.

Supplementary observations

(measurements based on nine specimens) in Table 2.

Comments.

Specific placement of current specimens are in agreement with diagnosis provided by MacCallum (1913) who described this species from A. probatocephalus obtained from a fish market (origin unknown) in New York City, USA. Caballero y Caballero and Bravo-Hollis (1972) erected Paramicrocotyle to describe P. tampicensis and P. atriobursata on Diapterus olisthostomus ( Gerreidae ) (now Diapterus auratus Ranzani, 1842) from Ciudad Madero, Tamaulipas (Gulf of Mexico) as well as accommodate whithin the genus other sixteen species previously placed in Microcotyle , including M. archosargi . However, all species of Paramicrocotyle were reassigned to Microcotyle by Mamaev (1986), who considered Paramicrocotyle a junior subjective synonym of Microcotyle. Currently, M. archosargi (sensu Mamaev 1986) has been recorded from sheepshead (as Archosargus oviceps ) taken at Alligator Harbor, Florida, by Hargis (1956); Iruegas-Buentello (1999) reported it from sheepshead in the Laguna Madre, San Fernando, Tamaulipas, Mexico; and Kritsky and Bakenhaster (2011) provided supplementary observations for M. archosargi based on examination of museum specimens and other specimens of this species collected on A. probatocephalus from the Indian River Lagoon near Malabar, Brevard County, Florida.

These latter authors stated that M. archosargi has two bilateral zones of small spines lying slightly posterior to the armed genital atrium, which are close to the ventral surface of the worm, but somewhat deeper within the body than those of the genital atrium. We fully concur in these morphological observations based on examination of present specimens (see Figure 5). Based on examination of five vouchers (CNHE 0323) of M. tampicensis (Caballero y Caballero & Bravo-Hollis, 1972), it shows to be extremely similar to the general characteristics of M. archosargi , particularly in having morphologically comparable genital atrium (see figures 7-12 in Caballero y Caballero and Bravo-Hollis 1972; figure D in MacCallum 1913; Figure 5 in the present study). The resemblance of both M. tampicensis and M. archosargi can be explained by the fact that the former was mainly described and/or differentiated of other congeneric species based on the structure and shape of the genital atrium. The two species are presently considered distinct based on the length of the genital atrium, i.e., 279 in M. tampicensis vs. 105-180 in M. archosargi (see Table 2).

However, the five vouchers of M. tampicensis were flattened and/or distorted (i.e., one specimen with distorted genital atrium, two specimens with incomplete haptor and another specimen was fragmented in three parts) due to coverslip pressure, which may have altered the length of the genital atrium. Determination of possible synonymy, therefore, will depend on recollection of the specimens of M. tampicensis from D. olisthostomus in the Gulf of Mexico for comparison with M. archosargi . In other features, present specimens of M. archosargi from A. rhomboidalis metrically fit within range from those specimens found on A. probatocephalus (see Table 2). Differences in the number of testes and clamps, morphologically identical in specimens of M. archosargi from different hosts and locations, are considered as intraspecific variation. Montoya-Mendoza et al. (2015) reported M. archosargi on A. probatocephalus in Veracruz, Mexico, without providing any accession reference number from the CNHE. Then, we could not corroborate finding of these latter authors.

Molecular data.

This study also provided the first molecular data for M. archosargi by adding a sequence (638 bp) of an individual specimen into the analyses. This sequence of M. archosargi on A. rhomboidalis from Campeche supports conspecificity of this monogenean with other microcotylids, i.e., Microcotyle sebastis Goto, 1894 reported on scorpaeniform hosts ( Sebastodes maliger Jordan & Gilbert, 1880, Sebastodes caurinus Richardson, 1844 and Sebastes sp.) from the UK, Japan, and USA; Microcotyle erythrini van Beneden & Hesse, 1863 and Microcotyle arripis Sandars, 1945 reported on perciformes ( Pagellus erythrini L.), and Arripis trutta (Forster, 1801) ( Kaouachi et al. 2010) (see Figure 6).

Specimens deposited.

Nine reference specimens in the CNHE (10611). Another slide containing haptor of a specimen of M. archosargi used to amplify its DNA is deposited in the CNHE (10626).

Representative DNA sequence.

GenBank accession number MG586867.